how change linerenderer with png or material....

i want change color with material or png how way??? so when launch the linerender become texture in the material...

i use the code

 var c1 : Color ;
 var c2 : Color ;
 var lengthOfLineRenderer : int ; 
 var materials : Material[]; 
 
 function Start() 
 {
     var lineRenderer : LineRenderer = gameObject.AddComponent(LineRenderer);
     lineRenderer.material = new Material (Shader.Find("Particles/Additive"));
     lineRenderer.SetColors(c1, c2 );
     lineRenderer.SetWidth(0.4,0.4);
     lineRenderer.SetVertexCount(lengthOfLineRenderer);
 }
 
 function Update() 
 {
     var lineRenderer : LineRenderer = GetComponent(LineRenderer);
 
     for(var j : int = 2; j < lengthOfLineRenderer; j++) 
     {
         var pos1 : Vector3 = Vector3(j* -1*1,j,0);
         lineRenderer.SetPosition(j, pos1);
     }
 }

Can you help me???