基于CAD编制的LSP小程序，其功能键是，绘制已有的墙体的中心线，以用于算出套内面积。操作是时，框选择，即可。-Based on CAD the establishment LSP scr ipt, its functional key is, the plan had the wall middle line, uses in showing a set of in area.When the operation is, the frame chooses, then.