我一直在为同样的问题而苦苦挣扎。当它只是提交按钮时，一切都很好。但是当我将其更改为图像（将类型=提交替换为类型=图像）或将图像样式设置为背景图像时，它就不起作用了。任何帮助不胜感激，谢谢。

.HTML

<form method='post' action='contact-form-proc.php' name='contactform' id='contactform'>
    <p>
    <label for='fullname'>Your Name:</label><br/>
    <input type='text' name='fullname' />
    </p>
    <p>
    <label for='email' >Email Address:</label><br/>
    <input type='text' name='email' />
    </p>
    <input type='submit' name='submit' value='' id='submit' />
</form>

.CSS

<style>
label{
font-family:Arial, Helvetica;
font-size:0.8em;
}
#submit{
    background-image:url('submitP.gif');
    height:2.5em;width:9em;
    border:0;
    display:block;
}
</style>

.PHP

<?php
if(empty($_POST['submit']))
{
    echo "Form is not submitted!";
    exit;
}
if(empty($_POST["fullname"]) ||
    empty($_POST["email"]))
    {
        echo "Please fill the form";
        exit;
    }
$name = $_POST["fullname"];
$email = $_POST["email"];
mail( 'info@xyz.com' , 'New form submission' , 
"New form submission: Name: $name, Email:$email"  );
header('Location: thank-you.html');

?>