js input标签只能输入数字

function dataRegex(){
var invoiceAmount = $("#input").val();

invoiceAmount = invoiceAmount.replace(/[^\d.]/g, ""); 
invoiceAmount = invoiceAmount.replace(/^\./g, "");
invoiceAmount = invoiceAmount.replace(/\.{2,}/g, ".");
invoiceAmount = invoiceAmount.replace(".", "$#$").replace(/\./g, "").replace("$#$", ".");
invoiceAmount = invoiceAmount.replace(/([0-9]+\.[0-9]{2})[0-9]*/, "$1");  
$("#input").val(input)
}

绑定 onchange="dataRegex()" onkeyup="dataRegex()"