function addChildToForm(child)
{
    var current = child;
    child++;
    document.getElementById('button'+ current).innerHTML = '';
    newchild  = '<table class="registrationform">';
    newchild += '<th colspan="5">Gegevens van het kind</th>';
    newchild += '</tr>';
    newchild += '<tr>';
    newchild += '<td>Geslacht</td>';
    newchild += '<td>Voornaam</td>';
    newchild += '<td>Achternaam</td>';
    newchild += '<td>Tussenvoegsel</td>';
    newchild += '</tr>';
    newchild += '<tr>';
    newchild += '<td class="small">';
    newchild += '<select name="gender_child['+ child +']" class="medium">';
    newchild += '<option value="M">Jongen</option>';
    newchild += '<option value="F">Meisje</option>';
    newchild += '</select>';
    newchild += '</td>';
    newchild += '<td>';
    newchild += '<input type="text" name="firstname_child['+ child +']">';
    newchild += '</td>';
    newchild += '<td>';
    newchild += '<input type="text" name="lastname_child['+ child +']">';
    newchild += '</td>';
    newchild += '<td>';
    newchild += '<input type="text" name="infix_child['+ child +']" class="small">';
    newchild += '</td>';
    newchild += '</tr>';
    newchild += '<tr>';
    newchild += '<td class="small">Geboortedatum</td>';
    newchild += '<td>Geboorteland</td>';
    newchild += '<td colspan="3">';
    newchild += 'Hoe lang woont het kind al in Nederland?';
    newchild += '</td>';
    newchild += '</tr>';
    newchild += '<tr>';
    newchild += '<td>';
    newchild += '<select name="day_child['+ child +']" class="day">';
                     newchild += '<option value="01">01</option>';
            newchild += '<option value="02">02</option>';
            newchild += '<option value="03">03</option>';
            newchild += '<option value="04">04</option>';
            newchild += '<option value="05">05</option>';
            newchild += '<option value="06">06</option>';
            newchild += '<option value="07">07</option>';
            newchild += '<option value="08">08</option>';
            newchild += '<option value="09">09</option>';
            newchild += '<option value="10">10</option>';
            newchild += '<option value="11">11</option>';
            newchild += '<option value="12">12</option>';
            newchild += '<option value="13">13</option>';
            newchild += '<option value="14">14</option>';
            newchild += '<option value="15">15</option>';
            newchild += '<option value="16">16</option>';
            newchild += '<option value="17">17</option>';
            newchild += '<option value="18">18</option>';
            newchild += '<option value="19">19</option>';
            newchild += '<option value="20">20</option>';
            newchild += '<option value="21">21</option>';
            newchild += '<option value="22">22</option>';
            newchild += '<option value="23">23</option>';
            newchild += '<option value="24">24</option>';
            newchild += '<option value="25">25</option>';
            newchild += '<option value="26">26</option>';
            newchild += '<option value="27">27</option>';
            newchild += '<option value="28">28</option>';
            newchild += '<option value="29">29</option>';
            newchild += '<option value="30">30</option>';
            newchild += '<option value="31">31</option>';
            newchild += '</select>';
    newchild += '<select name="month_child['+ child +']" class="month">';
    newchild += '<option value="01">januari</option>';
    newchild += '<option value="02">februari</option>';
    newchild += '<option value="03">maart</option>';
    newchild += '<option value="04">april</option>';
    newchild += '<option value="05">mei</option>';
    newchild += '<option value="06">juni</option>';
    newchild += '<option value="07">juli</option>';
    newchild += '<option value="08">augustus</option>';
    newchild += '<option value="09">september</option>';
    newchild += '<option value="10">oktober</option>';
    newchild += '<option value="11">november</option>';
    newchild += '<option value="12">december</option>';
    newchild += '</select>';
    newchild += '<select name="year_child['+ child +']" class="year">';
                    newchild += '<option value="1990">1990</option>';
                    newchild += '<option value="1991">1991</option>';
                    newchild += '<option value="1992">1992</option>';
                    newchild += '<option value="1993">1993</option>';
                    newchild += '<option value="1994">1994</option>';
                    newchild += '<option value="1995">1995</option>';
                    newchild += '<option value="1996">1996</option>';
                    newchild += '<option value="1997">1997</option>';
                    newchild += '<option value="1998">1998</option>';
                    newchild += '<option value="1999">1999</option>';
                    newchild += '<option value="2000">2000</option>';
                    newchild += '<option value="2001">2001</option>';
                    newchild += '<option value="2002">2002</option>';
                    newchild += '<option value="2003">2003</option>';
                    newchild += '<option value="2004">2004</option>';
                    newchild += '<option value="2005">2005</option>';
                    newchild += '<option value="2006">2006</option>';
                    newchild += '<option value="2007">2007</option>';
                    newchild += '<option value="2008">2008</option>';
                    newchild += '<option value="2009">2009</option>';
                    newchild += '<option value="2010">2010</option>';
            newchild += '</select>';
    newchild += '</td>';
    newchild += '<td>';
    newchild += '<input type="text" name="cob_child['+ child +']">';
    newchild += '</td>';
    newchild += '<td>';
    newchild += '<input type="text" name="yearsinholland_child['+ child +']" class="small"> jaar';
    newchild += '</td>';
    newchild += '</tr>';
    newchild += '<tr>';
    newchild += '<td colspan="2">';
    newchild += 'In welke mate spreekt uw kind Russisch? (van 1 tot 10)';
    newchild += '</td>';
    newchild += '<td colspan="2">';
    newchild += 'In welke mate begrijpt uw kind Russisch? (van 1 tot 10)';
    newchild += '</td>';
    newchild += '</tr>';
    newchild += '<tr>';
    newchild += '<td colspan="2">';
    newchild += '<input type="text" name="speaklevel_child['+ child +']" class="small">';
    newchild += '</td>';
    newchild += '<td colspan="2">';
    newchild += '<input type="text" name="understandlevel_child['+ child +']" class="small">';
    newchild += '</td>';
    newchild += '</tr>';
    newchild += '<tr>';
    newchild += '<td colspan="2">';
    newchild += 'In welke mate kan uw kind Russisch lezen? (van 1 tot 10)';
    newchild += '</td>';
    newchild += '<td colspan="2">';
    newchild += 'In welke mate kan uw kind Russisch schrijven? (van 1 tot 10)';
    newchild += '</td>';
    newchild += '</tr>';
    newchild += '<tr>';
    newchild += '<td colspan="2">';
    newchild += '<input type="text" name="readlevel_child['+ child +']" class="small">';
    newchild += '</td>';
    newchild += '<td colspan="2">';
    newchild += '<input type="text" name="writelevel_child['+ child +']" class="small">';
    newchild += '</td>';
    newchild += '</tr>';
    newchild += '<tr>';
    newchild += '<td colspan="2">';
    newchild += 'Welke hobbies heeft uw kind?';
    newchild += '</td>';
    newchild += '</tr>';
    newchild += '<tr>';
    newchild += '<td colspan="2">';
    newchild += '<textarea name="hobbies_child['+ child +']"></textarea>';
    newchild += '</td>';
    newchild += '<td>';
    newchild += '</tr>';
    newchild +=  '<tr>';
    newchild += '<td colspan="5" align="center" id="button'+ child +'">';
    newchild += '<input type="button" onclick="addChildToForm('+child+')" id="addChildButton"';
    newchild += 'value="Volgend kind inschrijven"/>';
    newchild += '</td>';
    newchild += '</tr>';
    newchild += '</table>';
    newchild += '</div>';
    newchild += '<br/>';
    newchild += '<div id="childInfo'+child+'">';
   
    document.getElementById('childInfo' + current).innerHTML = newchild;
}

function validate_registrationform_fields()
{
    var formfield = document.getElementById('registrationform').elements;
    var reason    = true;
    for(var i = 0; i < formfield.length; i++) {
        if ((!stristr(formfield[i].name, 'infix')) &&
            (formfield[i].name != 'prefix')
            ) {
            if(reason == true) {
                reason = validate_required(formfield[i]);
            } else {
                validate_required(formfield[i]);
            }
        }
    }
    return reason;
}

function validate_required(field)
{
    with (field) {
        if (value=='Dit is een verplicht veld'||value=="") {
            field.style.background = '#FF0000';
            field.style.color = '#FFFFFF';
            field.value = 'Dit is een verplicht veld';
            field.setAttribute('onclick', 'this.value="";this.style.color="#000000";this.style.background="#FFFFFF"');
            return false;
        }
        return true;
    }
}

function stristr (haystack, needle, bool) {
    var pos = 0;

    haystack += '';
    pos = haystack.toLowerCase().indexOf( (needle+'').toLowerCase() ); 
    if (pos == -1) {
        return false;
    } else {
        if (bool) {
            return haystack.substr( 0, pos );        
        } else {
            return haystack.slice( pos );
        }
    }
}