function for comparation of 2 images

Good evening!
i just wanted to share that code with all the forum
its my first function and i wanted you to tell me your opinion
thanks

;==============================[General]=================================

;ImageCompare is an ahk function created with ImageSearch.
;It can be used to check if two images are visible in an area of your choise.
;
;==========================[Build the function]========================
;
;The function can be formed as:
;ImageCompare("imagefile1",'imagefile2",dx,dy,(errors:=0) )
;
;-----------------------------------------------------------------------------------------------------------------------------------------
;imagefile1=The image file that script is firstly searching for
;
;imagefile2=The image that you want to find in an area,around imagefile1
;
;dx=the amount of 'x' pixels around imagefile1('x' coordinates of search area)
;
;dy=the amount of 'y' pixels around imagefile1('y' coordinates of search area)
;
;errors:  
;
;0: Image1 appears next to image2          <---When you call the function it MUST be :=0
;1: Image1 does not exists next to image2
;2: Cant locate at least one of the image files
;
;NOTE: If you want to find an image that appears in an area of 30 pixels around imagefile1,then:
; dx=dy=30.Its not calcuated as coordinateX=dx/2 (Supposing that imagefile1 is in the
; middle of 30 pixels )
;=============================[Tips]============================================
;1)Try use dx and dy depending on the size of images you are working with
;2)Use .png files.JPG lacks of quality
;=========================[ImageCompare.ahk]=====================================
ImageCompare(byref imagefile1,byref imagefile2,byref dx,byref dy,byref errors)
{
	;==Default settings|Please dont edit==
    errors := 1
	CoordMode,Mouse,Screen
	CoordMode,Pixel,Screen
	
	;==End default settings==
	
;Searching for first image (imagefile1)
	ImageSearch , FoundX , FoundY , 0 , 0 , A_Screenwidth , A_screenheight , %imagefile1%.png
	if errorlevel = 1
	     {
		 errors := 2 ; Image1 couldnt be found
         return errors
	     }
	else if errorlevel = 2
		 Magbox , Error at process
;If imagefile1 exists,searches for imagefile2
	else 
		{
			sleep 1000
			click %FoundX%,%FoundY%   ; clicks imagefile1.In case you dont want to click it,just add  ';' in front of this line
			sleep 1000
			; Calculating the area around imagefile1
			foundxx := foundx - dx            ; -dx pixels left from imagefile1              
			foundyy := foundy - dy            ; -dy pixels up from imagefile1
			foundplusxx := foundx + dx    ; +dx pixels right from imagefile1
			foundplusyy := foundy + dy    ; +dy pixels down from imagefile1
			Imagesearch ,FoundX2,FoundY2,%foundxx%,%foundyy%,%foundplusxx%,%foundplusyy%, %imagefile2%.png
			if errorlevel = 0
				{
					traytip,,%imagefile2% is next to %imagefile1%
					errors := 0
				}
			else if errorlevel = 1
				{
					errors := 1  ; Image2 does not exist at the selected area,around image1
					return errors
				}
			else 
				{
					errors := 2 ; Image2 couldnt be found           
					return errors
				}
		}
return errors
}