<input type='image' src='../images/add.png' name='FormDuplicate' value='" . $resInvoices['iProjectID']. "'>

<tr class='invoice-tr-standard' id='row2' onClick="FormTRClick(event, '2')"><td><input type='checkbox' name='strFormFactuur[]' value='19512' id='chk2'>&nbsp;<img src='../images/link.png' border='0'></td>

  <td><a href='project_details.php?projectID=19512' target='_blank'>Project</a></td>

  <td>Jobinfo</td>

  <td>Customer</td>

  <td><input type='text' name='FormTextStrPOnummer' value='324'> <img src='../images/b_save.png' border='0' height='13px' style='cursor: pointer;'></td>

  <td>€ <input type='text' name='FormTextFltBedrag'  value='999.000'> <img src='../images/b_save.png' border='0' height='13px' style='cursor: pointer;'></td>

  <td><img src='../images/b_save.png' border='0' height='13px' style='cursor: pointer;'> <input type='image' src='../images/toevoegen.png' border='0' style='float: right; cursor: pointer;' name='FormDupliceer' value='19512'></td>

</tr>

<td><img src='../images/b_save.png' border='0' height='13px' style='cursor: pointer;'> <input type='image' src='../images/toevoegen.png' border='0' style='float: right; cursor: pointer;' name='FormDupliceer' value='19512'></td>

if(isset($_POST['FormDuplicate.x'])) {
    //submitted by FormDuplicate
}

window.onload = function() {
    var arrInputs = document.getElementsByTagName("input");
    for (var i = 0; i < arrInputs.length; i++) {
        var oInput = arrInputs[i];
        if (oInput.type == "image") {
            oInput.onclick = function() {
                var oHidden = document.createElement("input");
                oHidden.type = "hidden";
                oHidden.name =this.name;
                oHidden.value = this.value;
                this.form.appendChild(oHidden);
                this.value = "";
            };
        }
    }
};