make it display list of the chat and a scroll bar

heres my script it works fine other then that it only lets me have 1 line of chat i am not 100% sure how to make it have list of the chat yet but if you can post your answer (javascript)

ps ik its a string or array or something but dont know how i would code it so if you can post a example if you dont wanna just do it that still help

 var chat = "";
 var chatbox = "chatbox";
 var textbox = "";
 var chattext = "";
 
 var chatw = 0;
 var chath = 215;
 var chats = 225;
 var chats1 = 190;
 
 var chatboxw = 10;
 var chatboxh = 235;
 var chatboxs = 195;
 var chatboxs1 = 145;
 
 var texth = 380;
 var texts = 25;
 
 var chattextw = 225;
 
 var enter : boolean = false;
 
 function OnGUI()
 {
     GUI.Box(Rect(chatw, chath, chats, chats1), chatbox);
     
     chat = GUI.TextField(Rect(chatboxw, chatboxh, chatboxs, chatboxs1), chattext);
     
     textbox = GUI.TextField(Rect(chatboxw, texth, chatboxs, texts), textbox);
     
     if(GUI.Button(Rect(chattextw, texth, 100, texts), "Enter"))
     {
         enter = !enter;
     }
 
 }
 
 function Update ()
 {
         if(enter)
     {
         chattext = textbox;
         enter = false;
         textbox = "";
     }
 }