Per prima cosa puoi controllare i dati all'origine
con javascript.

onKeyPress=\"return goodchars(event,'0123456789-+.,')\"

function getkey(e)
{
if (window.event) return window.event.keyCode;
else if (e) return e.which; else return null;
}

function goodchars(e, goods)
{
var key, keychar;
key = getkey(e);
if (key == null) return true;

// get character
keychar = String.fromCharCode(key);
keychar = keychar.toLowerCase();
goods = goods.toLowerCase();

// check goodkeys
if (goods.indexOf(keychar) != -1)
return true;

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

// else return false
return false;
}

Poi fai il controllo a valle con le regexp.