<input type="text" name="aaa" value="" onkeyup="this.value=this.value.replace(/\D/g,'');"
onafterpaste="this.value=this.value.replace(/\D/g,'')" />
<input type="text" name="aaa" value="" onkeyup="this.value=this.value.replace(/\D/g,'');"
onafterpaste="this.value=this.value.replace(/\D/g,'')" />