<SCRIPT LANGUAGE="JavaScript">
<!--
function chk(str){
var re = /^(\d{3})\.(\d{2})$/;
return re.test(str);
}
alert(chk("123.45"));
alert(chk("1234.45"));
alert(chk("123.452"));
alert(chk("123"));
alert(chk("abc.45"));
//-->
</SCRIPT>
<!--
function chk(str){
var re = /^(\d{3})\.(\d{2})$/;
return re.test(str);
}
alert(chk("123.45"));
alert(chk("1234.45"));
alert(chk("123.452"));
alert(chk("123"));
alert(chk("abc.45"));
//-->
</SCRIPT>
http://expert.csdn.net/Expert/topic/1922/1922536.xml?temp=.7183039