javascript - 表单验证问题-PHP中文网问答

下面错在什么地方，不可行

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>无标题文档</title>
<script src="jquery-1.7.2.min.js" type="text/javascript"></script>
<style>
.mgs{ color:#F00; display:none;}
</style>
</head>

<body>



<form action="http://www.99m.com" onSubmit="return nameddd;">

    <P class="p1"><input id="name" type="text" value="" onblur="indexname();" /><span class="mgs">用户名不能为空</span></P>
    <input type="submit" value="Submit" />

</form>





<script>

var nameddd = false;

function indexname(){
    
    var name = $('#name');
    var namevalue = $('#name').val();
    var g = /^.{3,8}$/;
    if(namevalue == ''){
        $('.mgs').show().html('用户名不能为空'); 
        var nameddd = false;
    }else if( !g.test(namevalue) ){
        $('.mgs').show().html('用户名3位到8位');
        var nameddd = false;
    }else{
        $('.mgs').hide();
        var nameddd = true;
    }
}


</script>


</body>
</html>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <title>无标题文档</title> <script src="jquery-1.7.2.min.js" type="text/javascript"></script> <style> .mgs{ color:#F00; display:none;} </style> </head> <body> <form action="http://www.99m.com" onSubmit="return indexname();"> <P class="p1"><input id="name" type="text" value="" onblur="indexname();" /><span class="mgs">用户名不能为空</span></P> <input type="submit" value="Submit" /> </form> <script> function indexname(){ var name = $('#name'); var namevalue = $('#name').val(); var g = /^.{3,8}$/; if(namevalue == ''){ $('.mgs').show().html('用户名不能为空'); return false; }else if( !g.test(namevalue) ){ $('.mgs').show().html('用户名3位到8位'); return false; }else{ $('.mgs').hide(); return true; } } </script> </body> </html>