Código Javascript
:
Ver original<input type="text" class="non_num" />
<script>
function controla_nn(elem)
{
elem.value = elem.value.replace(/[0-9]{1,}/, '');
}
// campos no-numericos
nn = document.getElementsByClassName('non_num');
for (i=0;i<nn.length;i++)
nn[i].onchange = (function(){
controla_nn(this);
});
</script>