Javascript 我能';t使用onsubmit按钮在<;p>;在表单的底部 形式 函数isValidUsername(){ var user_name=document.getElementById(“user_name”); var模式=/^[A-Za-z0-9]{8,15}/g; var patternreq_1=/[A-Z]/g; var patternreq_2=/[0-9]/g; if(模式测试(用户名)){ document.getElementById(“错误消息”).innertext=“”; 返回true; } else if(patternreq_1.测试(用户名)==false&&patternreq_2.测试(用户名)==false){ document.getElementById(“错误消息”)。innerText= “*请在用户名中包含大写字母和数字。”; 返回false; } else if(patternreq_1.test(user_name)=false&&patternreq_2.test(user_name)=true){ document.getElementById(“错误消息”)。innerText= “*请在您的用户名中包含大写字母。”; 返回false; } else if(patternreq_1.test(user_name)=true和&patternreq_2.test(user_name)=false){ document.getElementById(“错误消息”).innerText= “*请在您的用户名中包含一个数字。”; 返回false; } else if(用户名.长度

Javascript 我能';t使用onsubmit按钮在<;p>;在表单的底部 形式 函数isValidUsername(){ var user_name=document.getElementById(“user_name”); var模式=/^[A-Za-z0-9]{8,15}/g; var patternreq_1=/[A-Z]/g; var patternreq_2=/[0-9]/g; if(模式测试(用户名)){ document.getElementById(“错误消息”).innertext=“”; 返回true; } else if(patternreq_1.测试(用户名)==false&&patternreq_2.测试(用户名)==false){ document.getElementById(“错误消息”)。innerText= “*请在用户名中包含大写字母和数字。”; 返回false; } else if(patternreq_1.test(user_name)=false&&patternreq_2.test(user_name)=true){ document.getElementById(“错误消息”)。innerText= “*请在您的用户名中包含大写字母。”; 返回false; } else if(patternreq_1.test(user_name)=true和&patternreq_2.test(user_name)=false){ document.getElementById(“错误消息”).innerText= “*请在您的用户名中包含一个数字。”; 返回false; } else if(用户名.长度,javascript,forms,submit,Javascript,Forms,Submit,所有这些: <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <title>Form</title> <script type="text/ja

所有这些:

        <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">

<head>
<title>Form</title>
<script type="text/javascript">
function isValidUsername() {
    var user_name = document.getElementById("user_name");
    var pattern =/^[A-Za-z0-9]{8,15}/g;
    var patternreq_1 = /[A-Z]/g;
    var patternreq_2 = /[0-9]/g;

    if (pattern.test(user_name)){
        document.getElementById("error_message").innertext ="";
        return true;
    }

    else if (patternreq_1.test(user_name)==false && patternreq_2.test(user_name)==false){
            document.getElementById("error_message").innerText = 
                "*Please include a capitalized letter and a number in your user name.";
            return false;
    }
    else if (patternreq_1.test(user_name)==false && patternreq_2.test(user_name)==true){
            document.getElementById("error_message").innerText = 
                "*Please include a capitalized letter in your username.";
            return false;
    }
    else if (patternreq_1.test(user_name)==true && patternreq_2.test(user_name)==false){
            document.getElementById("error_message").innerText =
                "*Please include a number in your username.";
                return false;
    }
    else if (user_name.length<8){
            document.getElementById("error_message").innerText =
                "*Please include at least eight letters in your username.";
                return false;
    }

}
 </script>
</head>


<body>

<form  method="post" name="contact_form"  onSubmit="return isValidUsername()">
    <h1>Please Enter Your Name</h1>
    <p>Your Name: <input type="text" name="user_name" id="user_name"></p>
    <p><input type="submit" name="send" value="Submit"></p>
    <p id="error_message" value="Use InnerText">&nbsp;</p>
</form>


</body>
</html>
应该更多:

所有这些:

        <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">

<head>
<title>Form</title>
<script type="text/javascript">
function isValidUsername() {
    var user_name = document.getElementById("user_name");
    var pattern =/^[A-Za-z0-9]{8,15}/g;
    var patternreq_1 = /[A-Z]/g;
    var patternreq_2 = /[0-9]/g;

    if (pattern.test(user_name)){
        document.getElementById("error_message").innertext ="";
        return true;
    }

    else if (patternreq_1.test(user_name)==false && patternreq_2.test(user_name)==false){
            document.getElementById("error_message").innerText = 
                "*Please include a capitalized letter and a number in your user name.";
            return false;
    }
    else if (patternreq_1.test(user_name)==false && patternreq_2.test(user_name)==true){
            document.getElementById("error_message").innerText = 
                "*Please include a capitalized letter in your username.";
            return false;
    }
    else if (patternreq_1.test(user_name)==true && patternreq_2.test(user_name)==false){
            document.getElementById("error_message").innerText =
                "*Please include a number in your username.";
                return false;
    }
    else if (user_name.length<8){
            document.getElementById("error_message").innerText =
                "*Please include at least eight letters in your username.";
                return false;
    }

}
 </script>
</head>


<body>

<form  method="post" name="contact_form"  onSubmit="return isValidUsername()">
    <h1>Please Enter Your Name</h1>
    <p>Your Name: <input type="text" name="user_name" id="user_name"></p>
    <p><input type="submit" name="send" value="Submit"></p>
    <p id="error_message" value="Use InnerText">&nbsp;</p>
</form>


</body>
</html>
应该更多:

这是错误的:

if (pattern.test(user_name)){ ...
应在参数中添加单引号或双引号:

document.getElementById(error_message)
这是错误的:

if (pattern.test(user_name)){ ...
应在参数中添加单引号或双引号:

document.getElementById(error_message)

你实际上没有问题,所以我只是猜测一下。如果用户输入了一些好的内容,你还需要清除错误消息;也许还需要做一些其他的“如果”,以防止以后的错误覆盖以前的错误。总的来说,我建议进行一点重构来清理一些东西,并可能帮助你重新构建一些东西,以使其更好更简单一点。你实际上没有问题,所以我只是猜测一下。如果用户输入了一些好的内容,你还需要清除错误消息;也许还需要做其他的“如果”,以防止以后的错误覆盖以前的错误。总的来说,我建议进行一点重构来清理一下,并可能帮助你重新构建如果你使用Chrome,点击ctrl-shift-I;如果你使用Firefox,点击firebug扩展;如果你使用IE8,点击F12加上floatless所说的……我建议你投资一个好的浏览器调试器。它可以帮你省去几个小时的头痛。如果你使用Chrome,点击
ctrl-shift-i
;如果你使用Firefox,则获得firebug扩展;如果你使用IE8,则点击
F12