var form='myform' //Give the form name here

function SetChecked(val, chkName, formname) {
	 if (formname) {dml = document.forms[formname]}
	 else {dml = document.forms['myform']}
    //dml = document.forms['myform'];
    len = dml.elements.length;
    var i = 0;
    for(i = 0; i < len; i++) {
        if (dml.elements[i].name == chkName) {
            dml.elements[i].checked = val;
        }
    }
}