C# trigger problem

How i can make this Javascript code to work same C# i need this code for C# cos i use GUI and other stuff.

 function Update (){
     if(open == true){
         var target = Quaternion.Euler (0, DoorOpenAngle, 0);
         transform.localRotation = Quaternion.Slerp(transform.localRotation, target,
         Time.deltaTime * smooth);
     }
 
     if(open == false){
         var target1 = Quaternion.Euler (0, DoorCloseAngle, 0);
         transform.localRotation = Quaternion.Slerp(transform.localRotation, target1,
         Time.deltaTime * smooth);
     }
 
     if(enter == true){
         if(Input.GetKeyDown("f")){
             open = !open;
         }
     }
 }
 
 function OnTriggerEnter (other : Collider){
     if (other.gameObject.tag == "Player") {
         (enter) = true;
     }
 }
 
 function OnTriggerExit (other : Collider){
     if (other.gameObject.tag == "Player") {
         (enter) = false;
     }
 }