function SelectAll(id) {

    var TargetChildControl = "chkItemApprove";
    var frm = document.forms[0];
    
    for (i = 0; i < frm.elements.length; i++) {

        if (frm.elements[i].type == "checkbox" && frm.elements[i].id.indexOf(TargetChildControl,0) >= 0) {

            frm.elements[i].checked = document.getElementById(id).checked;

        }  

        }

    }