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;
}