I am calling a function on a click event. The return is getting multiplied each time.
btn.on('click', function(){
    $.when(foo()).then(funtion(value){
        console.log(value);
    });
});
function foo(){
    //some process
    return value;
}
When I click the first time I get one value printed. Second time I get two values and it keeps on increasing.
How to make it return only one value?