function numbersonly(myfield, e, dec)
{
	var key;
	var keychar;

	if (window.event)
	   key = window.event.keyCode;
	else if (e)
	   key = e.which;
	else
	   return true;
	keychar = String.fromCharCode(key);

	// control keys
	if ((key==null) || (key==0) || (key==8) ||
	    (key==9) || (key==13) || (key==27) )
	   return true;

	// numbers
	else if ((("0123456789").indexOf(keychar) > -1))
	   return true;

	// decimal point jump
	else if (dec && (keychar == "."))
	   {
	   myfield.form.elements[dec].focus();
	   return false;
	   }
	else
	   return false;
}