表单递交合法性检测-只允许填写字母

 1<script language="JavaScript">   
 2<!--   
 3function CheckForm()   
 4{   
 5if (document.form.yourname.value == "" )   
 6{   
 7alert ("请输入姓名！");   
 8return false;   
 9}   
10  
11var Letters = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"   
12for (i=0; i < document.form.yourname.value.length; i++)   
13{   
14var CheckChar = document.form.yourname.value.charAt(i);   
15CheckChar = CheckChar.toUpperCase();   
16if (Letters.indexOf(CheckChar) == -1)   
17{   
18alert ("请输入英文姓名！");   
19return false;   
20}   
21}   
22  
23}   
24// -->   
25</script>

1<form action="" method="post" name="form" onsubmit="return CheckForm()">
2<div align="center">
3<input name="yourname" type="text"/>
4<input name="submit" type="submit" value="submit"/>
5</div>
6</form>