// Copyright (c) 2006 by Whitelion v1.0 at 03.06.2006; 22:11

function changeText(text) {
a=text.value;
len=text.value.length;
for (i=0; i<len; i++) {
temp=parseInt(a.charCodeAt(i));
if(temp<48||temp>57) {
a=a.substring(0,(a.length-1));
len=len-1;
i=i-1; 
}
}
text.value=a;
}