实例化任意规格的桌子3张，并求出面积和体积

<script>
    var Table = {
        length: 80,
        width: 50,
        height: 200,
        Area :function () {
            var area= this.length*this.width;
            var volume=this.length*this.width*this.height;
            document.write("面积1:"+area);
            document.write('<br>'+"体积1:"+volume+'<br>');
            return Area ;
        }
    }
    Table.Area ();
</script>

　　

<script>
    var table = {
        length: 70,
        width: 50,
        height: 200,
        Area:function () {
            var area=this.length*this.width;
            var volume= this.length*this.width*this.height;
            document.write('<br>'+"面积2:"+area);
            document.write('<br>'+"体积2:"+volume+'<br>');
            return Area ;
        }
    }
    table.Area ();
</script>

　　

<script>
    var  table = {
        length:60,
        width: 50,
        height: 200,
        Area:function () {
            var area=this.length*this.width;
            var volume= this.length*this.width*this.height;
            document.write('<br>'+"面积3:"+area);
            document.write('<br>'+"体积3:"+volume);
            return Area;
        }
    }
    table.Area();
</script>