I am using a HP w1907 widescreen lcd monitor since 4 years.
Now abruptly 1-2 weeks befor it showed a very thin verticle line of white colour formarly the colour used to change but now it is white only.
after some days a new line appeared adjacent to it it was light red in colour.
Now yesterday a new blue coloured line appeared on the far left side.
I used snipping tool for taking snapshot and used a camera both the photos are attached and one could say that its the mistake of monitor but what exactly... It looks very awkward..
Thanks in advanced.

If you can't connect the monitor to another computer or video card to test if it is the culprit, see if you can see the problem when you run the monitor's built-in diagnostics. If it persists, it is the monitor. If it doesn't, then it is the video card - possibly with degrading video RAM.

@rubberman thanks for replying but when i turned cpu off and turned on the monitor it showed the lines..
so i can say it is the monitor
also i changed my video card last month only it has a video ram of 256 mb.
But I am not getting the way to solve it...