need to be a bit more precise.
Plus just a bit of advise you may attract more replys if you titled your thread.
On casting a circle-
A magic circle is circle or sphere of space marked out by practitioners of many branches of ritual magic, which they believe will contain energy and form a sacred space, or will provide them a form of magical protection, or both. It may be marked physically, drawn in salt or chalk, for example, or merely visualised. Its spiritual significance is similar to that of mandala and yantra  in some Eastern religions
this was taken from wikepedia