Gui.Button An argument is missing. ((Rest Of Code Works Fine Expt for this one Line.))

Hi, I'm trying to set a code that Turns on and off other buttons, Howerver seems to be an error on a single line, Gui bot that declairs "Exit" of my submition of Unlocking a character.

     //   ***************END OF START FUNCTION PROCEDE TO GUI BUTTONS AND UNLOCK VERIFACATION ONLINE DATABASE**************
 
     void OnGUI() { 
 
 float LeftMenuX = -250;
 float RightMenuX = 250;
 
 
         //Character 1 Purchase character and send information to database.
 
 
     //        ********************** Checked if Character1 has not been set to 0 *************************
 
 if(GUI.Button (new Rect(490,200,180,120), "Unlock")); //replace Text with GuiImage 
             {
                 hasMyFirstButtonBeenPressed = true;
 
             }
 
 //if you have clicked on the button it gives you the option to purchace or to quit.
 
 
                 if (hasMyFirstButtonBeenPressed)
                 {
                 GUI.Box(new Rect(90,330,320,200), "Please Enter Your Username To Confirm Purchase");
 //USERNAME INPUT FOR SECURITY AND IF PLAYER MAKES A MISTAKE.
 //    ******Please Enter Your Username To Varafy Unlocking******
 
                     GUI.Box(new Rect(18,50,900,10), "Please Enter Your Username To Confirm Purchase");
                     formcharacter1 = GUI.TextField ( new Rect(  (Screen.width /2f)-(((100)*(Screen.height/5))/100)+LeftMenuX
                                                          ,((300)*(Screen.height/5))/100 //y
                                                          ,((200)*(Screen.height/5))/100 //width
                                                          ,25f  ) //height
                                                     , formcharacter1);
                     //Update My Character Purchace.
                     if(GUI.Button ( new Rect(  (Screen.width /2f)-(((100)*(Screen.height/5))/100)+LeftMenuX ,((375)*(Screen.height/5))/100 , 316*0.58f ,75*0.58f) , "Unlock" ) //connect button
                        ) {
 
                 cashTest (); // performs Void of cashtest, checks to see is user has enough Gold REquired for Purchase.
 
             }
         
                     
 
             // Draw a button to exit the purchase
             if(GUI.Button ( new Rect(95,370,100,20,), "Exit"))
                 {
                     hasMyFirstButtonBeenPressed = false;
                     
                 }
         }