js keypress 对输入中文不响应

<html>
<script src="jquery.js"></script>
<script>
var rules = {};
function keyPress(e) {
	var decimal = /^\d{1,4}(\.\d{0,1})?$/;
	var value = $(this).val();
	var property = $(this).attr("id");
	if(value == "" || decimal.test(value)){
		rules[property] = value;
		return;
	} 
	if(rules.hasOwnProperty(property)){
		$(this).val(rules[property]);
	}else{
		$(this).val("");
	}
} 
$(function(){
$("input[type=text]").bind("input",keyPress);
$("input[type=text]").bind("propertychange",keyPress);
}); 

</script>
<input type="text" id="inputa"/>
</html>