BootWiki教程网
源代码：
点击运行
<!DOCTYPE html> <html> <head> <meta charset="utf-8"> <title>BootWiki 教程网</title> </head> <head> <script> function validateForm(){ var x=document.forms["myForm"]["fname"].value; if (x==null || x==""){ alert("姓必须填写"); return false; } } </script> </head> <body> <form action="demo-form.php" method="post" name="myForm" onsubmit="return validateForm()"> 姓: <input name="fname" type="text"> <input type="submit" value="提交"> </form> </body> </html>
运行结果