Why can't I add an image in my প্রশ্ন and answers??

Everytime I click "add an image" the screen wil go a little lighter and if I click again it goes back to normal! WHY?? Anyone else have this problemo? What must I do to add an image? অথবা is it my type of phone???

Oh yeah and it also does the same thing when I try to make a poll..help me plz!! THANX