egroupware/phpgwapi/js/fckeditor/editor/dialog/common/fcknumericfield.htc

<public:component lightweight="true">

<script language="javascript">

function CheckIsDigit()
{
	var iCode = event.keyCode ;

	event.returnValue =
		(
			( iCode >= 48 && iCode <= 57 )		// Numbers
			|| (iCode >= 37 && iCode <= 40)		// Arrows
			|| iCode == 8						// Backspace
			|| iCode == 46						// Delete
		) ;

	return event.returnValue ;
}

this.onkeypress = CheckIsDigit ;

</script>

</public:component>