4 line code not working!

this code is not working

javascript and 2d
it looks fine but it has error and wont play

im getting error;

Assets/water/belowg.js(25,7): BCE0005: Unknown identifier: ‘coll’.

#pragma strict
function OnTriggerEnter2D(other: Collider2D) {

  if (coll.gameObject.tag == "Wall")


This is because you have no variable in scope defined as “coll” your Collider2D parameter is being defined as “other” so you would need to use

if( other.gameObject.tag == "Wall" )