How do i change Background color of textbox when onfocus?

Question

i tried this code but its not working.. when i on-focus textbox it shows error

   function ChangeBgColor(obj, evt) 
    { 
            if(evt.type==\"focus\"         


        

Answer 1

JavaScript is not necessary for this task, just use css (:focus is supported since IE8)

https://developer.mozilla.org/en-US/docs/CSS/:focus

input { background: lightgray; }
input:focus { background: white; }

---

Only if this effect is absolutely needed also on < IE8 then JS (properly wrapped in a conditional comment) can be used, but even in this scenario it is recommended to keep off style from logic: e.g.

function ChangeBgColor(obj, evt) { 
    obj.className = (evt.type === "focus") ? "focus" : "";
}

and use this style

 input { background: lightgray; }

 input:focus, 
 input.focus { background: white; }