Restricting movement

programming
1

I’m having a problem with this. Heres the code I use to stop me from moving out of the bottom of the screen:

 
 //if the player moves below the stage area, move it back to the bottom of the stage
  if((this._y+this._height)>Stage.height){
    this._y=Stage.height-this._height;
  }

this (I think) makes you not able to move out the top of the screen:

 //if the player moves above the stage area, move it back to the top of the stage
  if(this._y<0){
    this._y=0;
  }

this stop the player from moving out the right side of the screen:

 
if((this._x+this._width)>Stage.width){
   this._x=Stage.width-this._width;
  }
  if(this._x<0){
   this.x=0;
  }

this one isn’t working though it stops you from moving out of the left of the screen:

 
   if((this._x+this._width)>Stage.width){
   this._x=Stage.width-this._width;
  }
  if(this._x>550){
   this.x=550;
  }

Thanks for helping.