function select_all(id){
	frm = document.getElementById(id);
	for(i=0;i<frm.length;i++){
		if(frm.elements[i].type=='checkbox'){
			frm.elements[i].checked = 1;
		}
	}
}

function unselect_all(id){
	frm = document.getElementById(id);
	for(i=0;i<frm.length;i++){
		if(frm.elements[i].type=='checkbox'){
			frm.elements[i].checked = 0;
		}
	}
}