Select/Deselect All Checkbox

function SelectAllCheckBox(){
for (var i = 0; i < document.forms(0).length; i++){
if (document.forms[0].elements[i].id.indexOf('checkboxname') != -1){
document.forms[0].elements[i].checked = true;
}}}

function RemoveAllCheckBox() {
for (var i = 0; i < document.forms(0).length; i++) {
if (document.forms[0].elements[i].id.indexOf('checkboxname') != -1) {
document.forms[0].elements[i].checked = false;
}}}