function GoToPage(control,eventTextBox,key,maxPage) {
   var theTextBox=document.getElementById(eventTextBox); 
   if (CheckPageIndex(theTextBox,maxPage)) {
       if (key.length > 0)
         location.href=DoUrlString(key,theTextBox.value);
      else
      __doPostBack(control,'Page$' + theTextBox.value);
   }
   event.returnValue=false;
   
}
function CheckPageIndex(eventTextBox,maxPage) {    
     var regExp=new RegExp("^\\s*(\\d+)\\s*$");
     if (regExp.test(eventTextBox.value)) {
     
          if(RegExp.$1<1||RegExp.$1>maxPage) {
             
             alert("页索引应在 1-" + maxPage +" 之间!");
             eventTextBox.select();
             return false;
          }       
      }
      else{
           alert('输入的页索引无效!');
           eventTextBox.select();
           return false;
      }
      return true;
}
function DoUrlString(key,value) { 
    var _key=key;
    var prms=location.search;
    if(prms.length==0) 
        return location.pathname+"?"+_key+"="+value;
        var params=prms.substring(1).split("&"); 
        var newparam=""; var found=false;
        for(i=0;i<params.length;i++) {
           if(params[i].split("=")[0]==_key){
              params[i]=_key+"="+value; found=true; break; 
           } 
        }
   if(found) return location.pathname+"?"+params.join("&");
   else return location+"&"+_key+"="+value;
}