thanks guys for replay,
in maya when apply an imageplane to the project in top-front-side view you see the imageplane behind the grid, so you can easly draw curve or work with geometry. that is default maya setting. please apply a imageplae to your new project and see how looks like in this three view and compare with my imageplane and than you see different. any way i found the solution. It is problem with videocard. i,m using laptop compaq
with integred videocard, so the videocard is not enough to display the image. so i need change my videocard. but it is unpossible.because it is laptop. I try with desktop computer with gforce 128 mb ram it is perfect.
so all laptop with integred videocard are display same problem . mostly with ATI videocard. so never ever buy a laptop without videocard (128-256mb ram).also Ati are very bad for 3d animation. I have to buy a new laptop cost me $2780 ,
thanks for all replay's . please in the future anyone has same problem tell them it is videocard. best and goodluck with animation