set camera problem

I have problems in setting up camera at a particular position. I have attached an object as HUD with Avtar and another object is kept on ground. Attached object has position of object which is kept on ground. so, When i try to set camera at that object then camera is not setting up on object. It goes somewhere else. Script for attached object is as follows :
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vector pos=<77.068,77.023,24.583>; //position of object which is on ground
default
{
touch_start(integer total_number)
{
llRequestPermissions(llGetOwner(),PERMISSION_CONTROL_CAMERA);
llOwnerSay("Touched";
llSetCameraParams([CAMERA_ACTIVE,TRUE, CAMERA_POSITION, pos+<0,0,4>,CAMERA_FOCUS, pos,CAMERA_POSITION_LOCKED,CAMERA_FOCUS_LOCKED]);
llSleep(5);
llClearCameraParams();
}
}
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And when i replace "pos" with llGetPos(), camera sets on Avtar correctly.
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llSetCameraParams([CAMERA_ACTIVE,TRUE, CAMERA_POSITION, llGetPos()+<0,0,4>,CAMERA_FOCUS, llGetPos(),CAMERA_POSITION_LOCKED,CAMERA_FOCUS_LOCKED]);
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Plz reply...
thanx in adv.

problem solved...
actually some parameters were missing frm llsetcamerparams function