Check if its a number

Description: This script checks the contents of a form box to ensure that its a number. If not, the submission of the form is canceled, and the surfer prompted to re-enter a valid number. This script requires NS 4.x or IE 4.x to function-all other browsers will simply not participate in the number checking.

Directions: Simply cut and paste the below code into the body section of your page.It contains a form with one box that is checked for "number validity". You can add in more form elements into the form, as you would with any other form.

Here is the code in this textbox

<form name="checknum" onSubmit="return checkban()"><br />Please enter your age:<br><br /><input type="text" name="pnum"><br /><input type="submit" value="Submit"><br /></form><br /><script language="JavaScript1.2"><br />/*Number check script-<br />By Manoj Jha (http://free-java-script-code.blogspot.com)<br />*/<br /><br />function checknumber(){<br />var x=document.checknum.pnum.value<br />var anum=/(^\d+$)|(^\d+\.\d+$)/<br />if (anum.test(x))<br />testresult=true<br />else{<br />alert("Please input a valid number!")<br />testresult=false<br />}<br />return (testresult)<br />}<br /><br /></script><br /><script><br />function checkban(){<br />if (document.layers||document.all||document.getElementById)<br />return checknumber()<br />else<br />return true<br />}<br /></script>