Unity - Limit Camera Movement XY axis - unity3d

Question

I have the following code which works really well for scrolling map using the draggable mouse. I am trying to define limits so that I cannot scroll too far in either the x or y co-ordinates. I've seen various examples of code, such as:
"transform.position.x = Mathf.Clamp(-100, 100);" though have not been able to incorporate it into the code. I am a bit of a beginner to all this and have just done a 2D tutorial animating zombies and have a camera that can scroll, but would like to add limits to how far it can scroll in any given directions.
Thanks heaps
Adam
using UnityEngine;
using System.Collections;
public class ViewDrag : MonoBehaviour {
Vector3 hit_position = Vector3.zero;
Vector3 current_position = Vector3.zero;
Vector3 camera_position = Vector3.zero;
float z = 0.0f;
// Use this for initialization
void Start () {
}
void Update(){
if(Input.GetMouseButtonDown(0)){
hit_position = Input.mousePosition;
camera_position = transform.position;
}
if(Input.GetMouseButton(0)){
current_position = Input.mousePosition;
LeftMouseDrag();
}
}
void LeftMouseDrag(){
// From the Unity3D docs: "The z position is in world units from the camera." In my case I'm using the y-axis as height
// with my camera facing back down the y-axis. You can ignore this when the camera is orthograhic.
current_position.z = hit_position.z = camera_position.y;
// Get direction of movement. (Note: Don't normalize, the magnitude of change is going to be Vector3.Distance(current_position-hit_position)
// anyways.
Vector3 direction = Camera.main.ScreenToWorldPoint(current_position) - Camera.main.ScreenToWorldPoint(hit_position);
// Invert direction to that terrain appears to move with the mouse.
direction = direction * -1;
Vector3 position = camera_position + direction;
transform.position = position;
}
}

Answer 1

What exactly is the error you are getting? I imagine it is something along the lines of being unable to modify the return value of position because it is not a variable.
If this is the case, you should however be able to set the whole position vector at once. So try something along the lines of this:
var pos = transform.position;
transform.position = new Vector3(
Math.clampf(pos.x, -100, 100),
Math.clampf(pos.y, -100, 100),
pos.z
);
You may need to swap around clamping Y and Z, depending on how you are using them.