<!DOCTYPE HTML>
<html>
<head><meta charset="windows-1251" /> </head>
<body>
<input class="digit" type="text" maxlength="8" name="ot" value="">
<input class="digit" type="text" maxlength="8" name="do" value="">
<script>
digits=document.getElementsByClassName("digit")
filter=function () {
if(/\D+/g.test(this.value)) this.value=this.value.replace(/\D+/g, "")
}
for(i in digits){if(/\d+/.test(i)) digits[i].oninput=filter}
</script>
</body>
</html>