用javascript实现用户登录验证的代码。

<script language=javascript>

function checkSubmit()

{

    if((document.form1.name.value)==”)

    {

        window.alert (‘姓名必须填写’);

        document.form1.name.select();

        document.form1.name.focus();

        returnfalse;

    }

    else

        returntrue;

}

</script>

<form name=”form1″ onsubmit=”javascript:returncheckSubmit()”>

<input type=”text” name=”name”>

</form>