I think this is a pretty easy to fix error made by a newb ( me

. Can anyone tell me why the call to "this.slideNext() " in the code below does not work. Apparently "this.slideNext() " is not a function?
Code:
function ScoopAnimation(_path, _start, _end, _delay){
this.start = _start
this.end = _end;
this.delay = _delay;
this.path = _path
this.currentFrame = _start;
this.slideNext() = function (){
this.currentFrame ++;
console.log(' next this.currentFrame : ' +this.currentFrame );
}
this.start= function ()
{
console.log('next this.start() : ' +this.currentFrame );
//THE NEXT LINE CAUSES THE ERROR!
this.slideNext()
}
this.start();
}