The result of step 1.3 and 1.6 are shown as totally different as inputting the same co-ordinate as img.x as 240 and img.y as 260 because Map Server Itasca only provide the imagemap of the displayed area at once.
At every zoom level it creates a new imagemap and if we query anything beyond this displayed imagemap, it will unable to display the result. This is the main cause of different results and this is the major disadvantage of thin client application.