I want to draw the wall of 10'x10'.the dimension is inner to inner.i want to know that how can i apply the inner to inner dimesion because when i draw the one wall that is ok but when i draw the second wall from the same end it takes the dimesion from center  to end.so if i want to draw the wall of 10' i have to draw the wall of 10'4" after that it takes the inner 10' dimesion  is there any solutiion so i can draw it of 10' directly.please reply