need code for buttons

{if(Input.GetButtonDown(“---------”))

that my code segment I need to make it the left mouse what do I put in the blank to that the left mouse triggers the event

You can use Input.GetButtonDown(“Fire1”) to get the left mouse button (at least with the default Input setting). You can also use Input.GetMouseButtonDown(0) - (0=left, 1=right, 2=middle).