Hi.. help with variables

var k = “0”; - This is my first frame.

On the screen I have 4 buttons and an empty movie clip with instance name - container.

btn1
btn2
btn3
btn4
Each button has following script -

on (release) {
play();
k = 1
}

Value of k changes with the button.

eg. btn3 has k = 3; btn4 has k = 4

The last frame has following script -

container.loadMovie(k+".swf");

I want to make this function such, that instead of putting in each button - k = 1 or k = 2 or k = 3… I want to compile one common script where value of k gets recognized from the instance name of the button so that… value of k when u hit button 4 is identified from the btn4.

Can some one help? The source file can be downloaded here.

If possible modify my file and attach.

Regards,