set_borders
Set borders around the current selected cell area.
Call:
excel_request("set_borders", int border_left,int border_top,int border_right,int border_bottom);
Here: border_left, border_top, border_right, border_bottom are variables that set whether or not there will be a border on the left, top, right and bottom, respectively. 1-yes, 0-no.
Calling without these arguments means setting all borders:
excel_request("set_borders");