- <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
- <html>
- <head>
- <title>Sample Code</title>
- <script type="text/javascript">
- function CheckIPAddress(MyIPAddress)
- {
- var CheckIP = /^\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}$/;
- if(CheckIP.test(MyIPAddress))
- {
- alert("Your IP Address Is Valid.");
- }
- else
- {
- alert("Your IP Address Is Not Valid.");
- }
- }
- </script>
- </head>
- <body bgcolor=#00ff00 alink=blue vlink=blue>
- <FORM name="windowEvent">
- IP Address : <input type="text" name="txtipaddress" />
- <input type="button" value="Check" name="btnIPAddress" onClick="CheckIPAddress(txtipaddress.value)" />
- </FORM>
- </body>
- </html>
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David ScherfgenPosted Nov 30, 2012, 2:12 PM
Hi, this regular expression doesn't make sure that the numbers are between 0 and 255. It would accept an IP address like 999.888.777.666, which is clearly wrong. See my article here, it contains a regex that does check for this: http://regex-for.com/ip-addresses/