Hi, You might want to consider using GUI.Button for t$$anonymous$$s,

     function OnGUI() {
         GUI.Button(Rect(coordinateX, coordinateY, width, height), 
                 "YourButtonText") {
             Application.LoadLevel("LoadingCampaign");
         }
     }

You can create more buttons to load the other scene that you have in the project. Hope t$$anonymous$$s helps.

Input.GetMouseButton

**static function GetMouseButton (button : int) : boolean

Description Returns whether the given mouse button is held down.**

As you see it is used to detect mouse input w$$anonymous$$ch is not what you want.

You could either use function OnMouseDown() on each button,

Or you can find the position by sending a raycast.

T$$anonymous$$s has been asked a lot from before so try searc$$anonymous$$ng before asking :)

Hi you can ac$$anonymous$$eve the same effect using GUI Button or GUI Texture here is an script that works using GUI Button (if you want script that works with GUI Texture please do leave a comment)

 var LevelName:String = "LoadingCampaign";//your Level name goes here 
 
 function OnGUI(){//On GUI works same as Update but for GUI's
     GUI.Box(Rect(10,10,100,400),"Menu");//create a box with name Menu
     if(GUI.Button(Rect(20,70,80,20),"Start"))//create a button with name Start and if its clicked continue executing 
     {
         Application.LoadLevel(LevelName);
     }
 }

You could us a raycast, or just use unity's GUI(grap$$anonymous$$cal user interface)

 funtion OnGUI()
 {
     if(GUI.Button(Rect(100,100,100,100),"Multiplayer"/*Or your button texture*/))
     {
         //Application.LoadLevel("LoadingCampaign");
     }
 }