急用!请各位帮忙
<script language="vbscript">
<!--
sub Submit_onclick()
set theform=document.myform1
if IsNumeric(theform.cpsm.value)=false then
msgbox "we"
end if
end sub
-->
</script>
<FORM action="ditch12.asp" method=post name="form1">
<INPUT class=smallInput maxLength=4 name="cpsm">
<INPUT class=buttonface name=Submit type=submit value="提交">
</FORM>
上述程序如果我在文本框里面输入不是有效的数字,将会弹出对话框,但是问题是如何让他不跳到要提交的页面“ditch12.asp”,请各位帮忙解决,谢谢!