function get_random_num(num_elements){
	// number from 1 . . . (num_elements)
	var i = Math.round((num_elements-1)*Math.random()) + 1;
	if (i < 10){
		i= '0' + i;
	}
	return i;
}

function get_topright_img(){
	document.write('<img src="imgs/rt_col_' + get_random_num(7) + '.jpg" id="rightcol_topimg" alt="right column img" />');
}
function get_leftcol_img(){
	document.write('<img src="imgs/left_col_' + get_random_num(7) + '.jpg" id="leftcol_img" alt="left col" />');
}
function get_midcol_img(){
	document.write('<img src="imgs/mid_col_' + get_random_num(7) + '.jpg" alt="middle column image" width="436" height="80" style="border:0; padding:0;" />');
}