how to add and remove css class

Question

how to remove CSS default class

This is my div

This is my css class

#messageContai         


        

Answer 1

You can approach it two ways. One, use two classes and literally swap them out for each other:

.red { background: red }
.green { background: green }

And then in jQuery:

$("#messageContainer").attr('class','green'); // switch to green
$("#messageContainer").attr('class','red'); // switch to red

Or you can use CSS order to toggle a single class:

#messageContainer { background: red }
#messageContainer.green { background: green }

Then:

$("#messageContainer").toggleClass("green");

That would alternate backgrounds every time it was called.