如何使用Javascript和Ajax更改div背景颜色？

Question

I am trying to change background color of div using Ajax and Javascript, but my code is not working:

Code:

<script type="text/javascript">
    window.rowcount=function() {
        var exam = new XMLHttpRequest();
        exam.onreadystatechange = function() {
            if (exam.readyState == 4) {                             
                var i=document.getElementById("newdata").innerHTML = exam.responseText;
                if(i==1){
                    document.getElementsById("newdata").style.backgroundColor = green;                  
                }

            }
        }
        exam.open("GET", "demo1.php?", true);
        exam.send(null);

</script>

Where am I wrong in this code?

Any help will be appreciated.

Answer 1

The problem is that green is not defined. You can use "green" or #00FF00 .

Try this:

    <script type="text/javascript">
    window.rowcount=function() {
        var exam = new XMLHttpRequest();
        exam.onreadystatechange = function() {
            if (exam.readyState == 4) {


                var i=document.getElementById("newdata").innerHTML = exam.responseText;
             if(i==1){
                  document.getElementsById("newdata").style.backgroundColor = "#00FF00";

             }

            }
        }
        exam.open("GET", "demo1.php?", true);
        exam.send(null);

    </script>

Answer 2

You forgot a bracet and green needs to be a string, so:

<script type="text/javascript">
  window.rowcount=function(){
    var exam=new XMLHttpRequest();
    exam.onreadystatechange=function(){
      if(exam.readyState==4){
        var i=document.getElementById("newdata").innerHTML=exam.responseText;
      }
      if(i==1){
        document.getElementsById("newdata").style.backgroundColor="green";
      }
    }
  }
  exam.open("GET", "demo1.php?", true);
  exam.send();
</script>

Answer 3

By Typing green You Pass in a variable. Type "Green" instead