function TotalAmount(field){
	for(i=0; i<document.PostOrder.c.length; i++){
		if (document.PostOrder.c[i].checked==true) {
			total = document.PostOrder.c[i].value; 
			document.getElementById(field).value = total;
		}
	}
	
}

function ClearAmount(field,field2,field3){
	document.getElementById(field).value = '';
	document.getElementById(field2).value = '';	
	document.getElementById(field3).value = '';	
}