How to translate something only on X axis on Y axis,once per mouse click?

So do you know the game Find a way, Juan?

It's a puzzle game,and I want to make somehow a copy of that,for a school project.

The thing is, once i click the mouse,i want the puzzle things to move ONLY left/right or up/down depending on if i started to move the mouse sideways or up and down. For example i want to move a piece a bit on the right. I click it,and move the piece to right. Only the X axis changes,the Y stays constant. If i want to move something,up or down,the X stays constant.

using UnityEngine; using System.Collections; public class slide : MonoBehaviour { // Use this for initialization void Start () { } // Update is called once per frame void Update () { if(Input.GetMouseButton(0)){ Vector3 initialPosition = this.transform.localPosition; Vector3 myPosition = Camera.main.ScreenToWorldPoint(Input.mousePosition)-this.transform.localPosition; Vector3 sndPosition = Camera.main.ScreenToWorldPoint(Input.mousePosition) - this.transform.localPosition; if (Mathf.Abs(initialPosition.x-myPosition.x - sndPosition.x) > Mathf.Abs(initialPosition.y-myPosition.y - sndPosition.y)) { myPosition.y = 0; } else { myPosition.x = 0; } myPosition.z = 0; transform.Translate(myPosition); } } }

The thing is,I cant fighre it out,how to stop checking the absolute values once the mouse has moved.