Protectascreen

can't use empty string as operand of "+"
    while executing
"expr {$prod_price+$option_price}"
    ("foreach" body line 14)
    invoked from within
"foreach product $man_category_products {
						lassign $product prod_id prod_title prod_image prod_priority prod_price 

    					set product_options ..."
    ("foreach" body line 13)
    invoked from within
"foreach man_cat $man_categories {
				lassign $man_cat man_cat_id man_cat_title
				html [subst {