Why is the Object reference is empty ?

Hello, I posted a similar question before, couldnt get an answer. What I am trying to do is a very common thing I believe, and should be easy to solve but somehow I just cant.

Whene I call an instance of script A, in script B, if I try to access its properties, I always get Object reference is null exception, which I dont understand why. Here is one of those places taht I try to do it.

 void OnGUI()
 {
     if(GUI.Button(new Rect(10,10,100,100),"blas"))
     {
         CameraShooot other = gameObject.GetComponent<CameraShooot>();
         
         if(other != null)
             other.selectedTexture = (Texture)Resources.Load("ege2");
     }            
 }

Would be really happy if someone can tell me what am I doing wrong ? Why 'other' variable seems to be null all the time ? If anyone asks, 'selectedTexture' is a Texture type public variable which is instatiated with new Texture() and all..

Thanks.