Your response is almost certainly a string. You need to make sure it gets converted to a number: document.getElementById("points").value= ... ... <看更多>

Introduction to JavaScript getElementById() method ... The document contains a <p> element that has the id attribute with the value message :. ... <看更多>

What is Document.getElementById in javascript and how does it work. ... <看更多>

You need to use var ddate = document.getElementById('testme').value; instead as val() is a jquery-function and not available in native ... ... <看更多>

JavaScript document.getElementById. If you want to quickly access the value of an HTML input give it an id to make your life a lot easier. This small script ... ... <看更多>

val(12345); var number = document.getElementById("number"); number.value = ... ... <看更多>