Changing background color of text box input not working when empty

Question

I am having a tough time with this javascript code to change the background color of a text input if the input is empty.

Here is the code:

function c         


        

Answer 1

on body tag's onLoad try setting it like

document.getElementById("subEmail").style.backgroundColor = "yellow";

and after that on change of that input field check if some value is there, or paint it yellow like

function checkFilled() {
var inputVal = document.getElementById("subEmail");
if (inputVal.value == "") {
    inputVal.style.backgroundColor = "yellow";
            }
    }