function chkForm() {
			var obj = document.getElementById("sch");
			if (obj["zipcode"].value.length < 1 && obj["City"].value.length < 1 && obj["Center"].value.length < 1 ) 
				{
				alert("Please, enter the center information");
				obj["zipcode"].focus();
				return false;
				}
			if ( chkString("City") != true ) return false;
			if ( chkString("Center") != true ) return false;
				return true;
		}
		function isNumeric(str) {
			var obj = document.getElementById("sch");
			if ((/[^0-9]/g).test(obj[str].value))
			{
			alert("Please use only numbers.")
			obj[str].value = "";
			obj[str].focus();
			}	
		}
		function isSpecialChr(str) {
			var strChk = str;
			var result = (/[^a-zA-Z0-9-_\s]/g).test(strChk);
			return ( result );
		}
		function chkString(str){
			var obj = document.getElementById("sch");
			var strCity = obj[str].value
			if ( isSpecialChr(strCity) ) {
				alert(str+" name can not include Special Character. Please input again.");
				obj[str].value = strCity.substring(0,strCity.length-1);
				obj[str].focus(); 
				return false;
			}
			return true;
		}