table.canvas { }

table.canvas td.right_top { width:14px; height:14px; background-image:url('/images/canvas/top_right.gif'); }
table.canvas td.left_top { width:14px; height:14px; background-image:url('/images/canvas/top_left.gif'); }
table.canvas td.right_bottom { width:14px; height:14px; background-image:url('/images/canvas/bottom_right.gif'); }
table.canvas td.left_bottom { width:14px; height:14px; background-image:url('/images/canvas/bottom_left.gif'); }

table.canvas td.left { background-image:url('/images/canvas/left.gif'); }
table.canvas td.right { background-image:url('/images/canvas/right.gif'); }
table.canvas td.top { background-image:url('/images/canvas/top.gif'); }
table.canvas td.bottom { background-image:url('/images/canvas/bottom.gif'); }