parameter passing from view to controller via anchor

[eluser]Lakshminarayanank[/eluser]
Hi all... I am a fresher to CI.. using with mysql
I am facing a difficulty in passing and accessing the parameter.
here is ma code..

in a view :
$d = array('proj_id'=>$pid)
echo anchor('aims/view_project',$pid,$d)

in controller am accessing it..
function view_project()
{
echo 'project no is' .$proj_id;
}

Am getting undefined symbol proj_id error message .. i got helg up there...
pls help me...!!