The Lasso tool allows you to select a non-uniform area of the image by drawing the shape freehand with the mouse.
To use this tool...
Click on the Lasso button. Position the crosshairs of the cursor at any point around the area to be selected and hold down the left mouse button. Draw the shape of the desired selection by moving the mouse. Once the mouse button is released, Paint Shop Pro will automatically connect the start and end points.