input的onchange事件 及只能输入数字实现

<input type="text" class="currentPage">
<script>
// method1
$(".currentPage").on('input',function(e){
alert("TextChanged!") ;
});
//method2
$(".currentPage").bind("propertychange input",function(){
alert("TextChanged!") ;
})
</script>

<input id="xxx" type="number" onKeypress="return (/[\d]/.test(String.fromCharCode(event.keyCode)))"/>

<input id="xxx" type="number" onKeypress="return (/[\d+([.]\d)]/.test(String.fromCharCode(event.keyCode)))"/>

$("#withdrawAmount").change(function(){
if (utils.isEmpty(this.value)){
this.value = 0;
} else if (this.value > can_out_amount){
var s_amount = can_out_amount.toString();
this.value = s_amount;
if (s_amount.indexOf('.') > 0) {
this.value = s_amount.substring(0, s_amount.indexOf('.'));
}
}
});