<script language="javascript">
function numberObject(on,n){
var value=Math.round(parseFloat(on.value)*n)/n
if(!value){
value="";
}
on.value=value;
}
</script>
<input id="sbp" type="text"
onkeyup="value=value.replace(/[^0-9]/,'')"
<!-- 替换所有非数字的字符为‘’-->
onblur="numberObject(this,1)"
/ >