function   Check()   
  {   
    
      if   (document.form.username.value   ==   "")   
      {   
          alert("请输入用户名！");   
         document.form.username.focus();   
          return  false;   
      }   
    	 if   (document.form.password.value   ==   "")   
      {   
          alert("请输入密码！");   
         document.form.password.focus();   
          return  false;   
      }   
    	 if   (document.form.code.value   ==   "")   
      {   
          alert("请输入验证码！");   
         document.form.code.focus();   
          return  false;   
      }   
      return  true; 
  }  
  
function MM_openBrWindow(theURL,winName,features) { //v2.0
  window.open(theURL,winName,features);
}