JavaScript Tutorial/Global/isNaN
Global.isNaN()
Syntax
<source lang="javascript">
isNaN(variable)</source>
Use isNaN to check if the input is a number
<source lang="javascript">
<html> <head> <title>The NaN property of the Number object</title> <script type="text/javascript" language="javascript">
</script> </head> <body onload="Calculate()"> </body> </html></source>
