try:
<form method="POST" action="1.asp" onkeydown="return event.keyCode!=13">
<input type="text"><input type="submit" value="提交">
</form>
<form method="POST" action="1.asp" onkeydown="return event.keyCode!=13">
<input type="text"><input type="submit" value="提交">
</form>
if(event.keyCode=13)
{
retiurn false
}