function getCookieVal(offset)
{ 
     var endstr = document.cookie.indexOf (";", offset); 
     if (endstr == -1) endstr = document.cookie.length;
     return unescape(document.cookie.substring(offset, endstr)); 
}
function GetCookie(name) 
{ 
     var arg = name + "="; 
     var alen = arg.length;
     var clen = document.cookie.length; 
     var i = 0; 
     while (i < clen) 
     { 
          var j = i + alen; 
          if (document.cookie.substring(i, j) == arg) 
          return getCookieVal (j); 
          i = document.cookie.indexOf(" ", i) + 1; 
          if (i == 0) break; 
     } 
      return ""; 
} 
function SetCookie (name, value) 
{ 
     var argv = SetCookie.arguments; 
     var argc = SetCookie.arguments.length; 
     var expires = (argc > 2) ? argv[2] : null;
     var path = (argc > 3) ? argv[3] : null; 
     var domain = (argc > 4) ? argv[4] : null; 
     var secure = (argc > 5) ? argv[5] : false; 
     document.cookie = name + "=" + escape (value) + ((expires == null) ? "" : ("; expires=" + expires.toGMTString())) + ((path == null) ? "" : ("; path=" + path)) + ((domain == null) ? "" : ("; domain=" + domain)) + ((secure == true) ? "; secure" : "");
}
function DeleteCookie (name) 
{ 
     var exp = new Date(); 
     exp.setTime (exp.getTime() - 1); 
     var cval = GetCookie (name); 
     document.cookie = name + "=" + cval + "; expires=" + exp.toGMTString(); 
}
function isEmail(strEmail)
{
	if (strEmail.search(/^\w+((-\w+)|(\.\w+))*\@[A-Za-z0-9]+((\.|-)[A-Za-z0-9]+)*\.[A-Za-z0-9]+$/) != -1)
		return true;
	else
		return false;
}
/*短时间，形如 (13:04:06)*/
function isTime(str)
{
	var a = str.match(/^(\d{1,2})(:)?(\d{1,2})\2(\d{1,2})$/);
	if (a == null) 
	{	
		str+=":00";
		a = str.match(/^(\d{1,2})(:)?(\d{1,2})\2(\d{1,2})$/);
		if (a == null) 
		{
			return false;
		}
	}
	if (a[1]>24 || a[3]>60 || a[4]>60)
	{
		return false;
	}
		return true;
}
/*短日期，形如 (2003-12-05)*/
function isDate(str)
{
    var r = str.match(/^(\d{1,4})(-|\/)(\d{1,2})\2(\d{1,2})$/); 
    if(r==null)return false; 
    var d= new Date(r[1], r[3]-1, r[4]); 
    return (d.getFullYear()==r[1]&&(d.getMonth()+1)==r[3]&&d.getDate()==r[4]);
}
/*长日期，形如 (2003-12-05 13:04:06)或(2003-12-05 13:04)*/
function isDateTime(str)
{
	var reg = /^(\d{1,4})(-|\/)(\d{1,2})\2(\d{1,2}) (\d{1,2}):(\d{1,2}):(\d{1,2})$/;
	var r = str.match(reg);
	if(r==null)
	{
		str=str+":00";
		r = str.match(reg);
		if(r==null)
			return false;
	}
	var d= new Date(r[1], r[3]-1,r[4],r[5],r[6],r[7]);
	return (d.getFullYear()==r[1]&&(d.getMonth()+1)==r[3]&&d.getDate()==r[4]&&d.getHours()==r[5]&&d.getMinutes()==r[6]&&d.getSeconds()==r[7]);
}
function trim() 
{
	return this.replace(/\s+$|^\s+/g,"");
}

function ltrim() 
{
	return this.replace(/^\s+/,"");
}

function rtrim() 
{
	return this.replace(/\s+$/,"");
}
String.prototype.trim=trim;
String.prototype.rtrim=rtrim;
String.prototype.ltrim=ltrim;

function ChangeIMG(img)
{/*此方法用于改变验证码*/
    var d=new Date();
    img.src="ValidImage.aspx?flag="+d;
}