add link to the Form search easy job for php dev

i have a form search , i want make a edit to it then its search for iphone 6 its give example freetextsearch/search/result/?keyword=iphone+6 so what i want to add this ?cat=1323& before keyword=iphone+6 so the result will be like this freetextsearch/search/result/?cat=1323&keyword=iphone+6 this easy job for someone who know about PHP i will pay 5 dollars for this job... I WILL TEST THE CODE FIRTS AND THEN PAY IF ITS WORK PLEASE DONT APPLY IF YOU DONT ACCEPT THIS .. thanks