js

<script type="text/javascript" src="NewLogin/js/jquery-1.3.2.min.js"></script>
		<script type="text/javascript" src="NewLogin/js/jquery-1.3.2-vsdoc.js"></script>
		<script language="javascript">
		 //login
		 function CheckLogin()
		 {
		   if(document.all("TxtUser").value=="")
		   {
		    alert("请输入用户名!");
		    document.all("TxtUser").focus();
		    return false;
		   }
		   else 
		   {
		     if( CheckUserName(document.all("TxtUser").value)==false )
             {
              alert("用户名必须是字母数字和下滑线");
              return false;
             }       
		   
		   }
		   
		   
		   if(document.all("TxtPass").value=="")
		   {
		    alert("请输入密码!");
		    document.all("TxtPass").focus();
		    return false;		   
		   }
		   
		  return  TimeAdd();
		 
		 }
		 
		 //clear text
		function Cleartext()
		{	    
		    document.all("TxtUser").value = "";
		    document.all("TxtPass").value = "";
		    document.all("txtValidte").value = "";
		    return false;
		}
		 
		//check username       
       function CheckUserName( str )
       {
           var reg = /^\w+$/ ;
           return Check( reg, str);
       
       }       
      
       //check
       function Check( reg, str )
       {
	          if( reg.test( str ) )
	          {
		         return true;
	          }
	      return false;
       }
       
       
		function change(img)
		{
		   var now=new Date(); 
           var number = now.getSeconds(); 
		   img.src=img.src+"?"+number;
		}
		
		//回车
        function CheckGo()
        {
            if(window.event.keyCode == '13')
            {
               $("#<%=ButtnLogin.ClientID %>").click();
                event.keyCode=0;
                event.returnValue=false;
            } 
        }   
       
       function getEnter(){
       if(event.keyCode == 13 && event.srcElement.type!='submit'){
        event.returnValue=false;
        document.getElementById("<%=ButtnLogin.ClientID %>").click();
       } 
      }
      
       //Automatic Speaking time
		var MAX_IDIOT_SECONDS = 1200;  //最大延时时间(秒)		

		function _startCount() {
		var objSeconds = document.getElementById('seconds');
		var dtStart = new Date();		
		var timer = setInterval(function() {
		var dtNow = new Date();
		var seconds = Math.round((dtNow.getTime() - dtStart.getTime()) / 1000);
				
		if(seconds > MAX_IDIOT_SECONDS) {	
		objSeconds.value = seconds;
		//alert(seconds+'   111');	
		//alert(objSeconds.value+'  222');
		
		clearInterval(timer);
		}
		}, 1000);
		}

		function  TimeAdd() {		
		var execTimer;
		
		var objSeconds = document.getElementById('seconds');		
		//alert(objSeconds.value+'  333');
		
		if(objSeconds.value > 1199)
		{		 
		  var objCodeImg = document.getElementById('CodeImg');
		  change(objCodeImg);
		  
		  if (execTimer) {
			clearTimeout(execTimer);
			}
			execTimer = setTimeout(function() {
			_startCount();
			}, 200);
		
		
		  alert('验证码超时,请重新输入验证码!');
		  document.all("txtValidte").value = "";	  
		  objSeconds.value = '0';
		   return false;		
		}else
		{
		   return true;		
		}	 
		
		}	
		</script>
		<script language="javascript" for="document" event="onkeydown">
         if(event.keyCode==13 && event.srcElement.type!='button' && event.srcElement.type!='submit' && event.srcElement.type!='reset' && event.srcElement.type!='textarea' && event.srcElement.type!='')
            event.keyCode=9;   //Tab的键值为9 Enter的键值为13.
		</script>
原文地址:https://www.cnblogs.com/Leo_wl/p/1732849.html