function checkLogin() { if(myform.u_name.value=="") { alert("用户名不能为空!"); myform.u_name.focus(); return false; } if(myform.u_password.value=="") { alert("密码不能为空!"); myform.u_password.focus(); return false; } } document.writeln(" "); document.writeln(" "); document.writeln(" "); document.writeln(" "); document.writeln(" "); document.writeln(" "); document.writeln(" "); document.writeln(" "); document.writeln(" "); document.writeln(" "); document.writeln(" "); document.writeln(" "); document.writeln(" "); document.writeln(" "); document.writeln("
   用户名:
   密 码:
"); document.writeln(" "); document.writeln(" "); document.writeln(" "); document.writeln(" "); document.writeln(" "); document.writeln("
"); document.writeln(" ");