function checkAll(elm)
{
    var form = elm.form;
    var elms = form.getElementsByTagName('input');
    
    for (var i = 0; i < elms.length; i++ ) {
        if (elms[i].type == 'checkbox') {
            elms[i].checked = elm.checked;
        }
    }    
}


function setCheckbox(elm,elmid)
{
    if(elmid == '') return true;
    var inputElm = document.getElementById(elmid);

    if(inputElm.type == 'checkbox') {
        if(elm.value != '')
            inputElm.checked = true; 
        else
            inputElm.checked = false;             
    }   
}


function formSubmit(formObject, frm_action)
{  
    if(validateInput(formObject))  {
        if(document.getElementById('frm_action')) {
            document.getElementById('frm_action').value = frm_action;
            formObject.submit();
        }
    }        
}


function validateInput(formObject)
{
    var elms = formObject.getElementsByTagName('input');
    var total = 0;
    var performSetCheck = false;
    
    for (var i = 0; i < elms.length; i++ ) {
        var classNames =  getClassNames(elms[i]);
        for (var j = 0; j < classNames.length; j++ ) {
            switch(classNames[j]) {
                case 'numeric':
                    if(! isNumeric(elms[i].value) && elms[i].value != '')
                    {
                        alert('Alleen numerieke waarden zijn toegestaan.');
                        elms[i].value = '';
                        elms[i].focus();
                        return false;
                    }
                    break; 
                    
                 case 'setcheck':
                    total = (total * 1) + (elms[i].value * 1);
                    performSetCheck = true;
                    break;                          
            }
        }
    }

    // check if anything is filled in
    if(performSetCheck == true && total == 0) { 
        alert('U heeft geen enkele waarde ingevuld.');
        return false;
    }    
    return true;    
}


function getClassNames(elm)
{
    return elm.className.split(' ');
}


function isNumeric(strString) 
{
    var strValidChars = "0123456789";
    var strChar;
    var blnResult = true;

    if (strString.length == 0) return false;

    //  test strString consists of valid characters listed above
    for (i = 0; i < strString.length && blnResult == true; i++)
    {
      strChar = strString.charAt(i);
      if (strValidChars.indexOf(strChar) == -1)
      {
         blnResult = false;
      }
    }
    return blnResult;
}