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;
}