function searchCity(obj, num){
	if (num==0){
		document.getElementsByName(obj)[0].checked=true;
		for (i=1; i<document.getElementsByName(obj).length; i++){
			document.getElementsByName(obj)[i].checked=false;
		}
	}else{
		document.getElementsByName(obj)[0].checked=false;

		if (document.getElementsByName(obj)[num].checked==false){
			document.getElementsByName(obj)[num].checked=false;

			var checkSel=0;
			for (i=1; i<document.getElementsByName(obj).length; i++){
				if (document.getElementsByName(obj)[i].checked==true){
					checkSel++
				}
			}
			if (checkSel==0){
				document.getElementsByName(obj)[0].checked=true;
			}
		}else{
			document.getElementsByName(obj)[num].checked=true;
		}
	}
}