function CheckDate(str){	
	if(str.length != 0){
		var reg = /^([0-9]{4})-([0-9]{2})-([0-9]{2})$/; 
		var r = str.match(reg); 
		if(r==null){
			alert("请输入正确的日期格式，如 2007-04-07");
			return false;
		} 
		r[2]=r[2]-1; 
		var d= new Date(r[1],r[2],r[3]); 
		var year= d.getFullYear();
		var month= d.getMonth();
		var date= d.getDate();
		if(month.length ==1){month='0' + year;}
		if(date.length ==1){date='0' + year;}
		
		if(year!=r[1]){
			alert("请输入正确的日期格式，如 2007-04-07");
			return false;
		}
		if(month!=r[2]){
			alert("请输入正确的日期格式，如 2007-04-07");
			return false;
		}
		if(date!=r[3]){
			alert("请输入正确的日期格式，如 2007-04-07");
			return false;
		}
	} 
	return true;
}


function trim(inputString) {
	if (typeof inputString != "string") { return inputString; }
		var retValue = inputString;
		var ch = retValue.substring(0,1);
		while (ch == " ") { 
			//
			retValue = retValue.substring(1, retValue.length);
			ch = retValue.substring(0, 1);
		}
		ch = retValue.substring(retValue.length-1, retValue.length);
		while (ch == " ") {
			//
			retValue = retValue.substring(0, retValue.length-1);
			ch = retValue.substring(retValue.length-1, retValue.length);
		}
		while (retValue.indexOf("  ") != -1) { 
			//
			retValue = retValue.substring(0, retValue.indexOf("  ")) + retValue.substring(retValue.indexOf("  ")+1, retValue.length); 
		}
	return retValue;
}