This code crashes unity, please help!

I use this code to generate a world in space of 500x500 and to then load it, it's not finished but for some reason it crashes when i start the GenerateWorld(); function.

 var generate : boolean = false;
 var load : boolean = false;
 var objects : GameObject[];
 var world = new Array(500);
 /*
 1 - sun
 2 - home planet (UNIQUE)
 3 - BLACK HOLE
 4 -> 11 - normal planet
 12 -> 15 - hot planet
 16 - cold planet
 */
 
 function SpaceCheck(x : int, y : int)
 {
     for(var i = x-3; i <= x+3; i++)
     {
         for(var j = y-3; j <= y+3; j++)
         {
             if(world[i][j]!=0)
             {
                 return 0;
             }
         }
     }
     return 1;
 }
 
 function GenerateWorld()
 {
     Debug.Log("Starting to generate");
     world[250][250] = 1;
     world[243][250] = 2;
     Debug.Log("Created home planet and solar system");
     for(var i = 20; i <= 480; i++)
     {
         for(var j = 20; j < 480; j++)
         {
             Debug.Log(i+" "+j);
             var a : float = Random.Range(0.0, 10.0);
             if(a >= 9.0)
             {
                 Debug.Log("Generated a Star");
                 world[i][j] = 1;
                 for(var k = i-10; k <= i+10; k++)
                 {
                     for(var l = j-10; l <= j+10; l++)
                     {
                         var b : float = Random.Range(0.0,10.0);
                         
                         if( (i-k)*(i-k)+(l-j)*(l-j)>=18 && b>=7.0)
                         {
                             if(SpaceCheck(k,l))
                             {
                                 var planet : int = 0;
                                 var dist : int = (i-k)*(i-k)+(l-j)*(l-j);
                                 if(dist >=18 && dist <=40)
                                 {
                                     planet = Random.Range(12,15);
                                 }
                                 if(dist>40 && dist <=150)
                                 {
                                     planet = Random.Range(4,11);
                                 }
                                 if(dist>150)
                                 {
                                     planet = 16;
                                 }
                                 world[k][l] = planet;
                             }
                         }
                     }
                 }
             }
         }
     }
     Debug.Log("done generatin");
 }
 
 function GetWorldData()
 {
     Debug.Log("done getting info");
 }
 
 function LoadWorld()
 {    
     for(var i = 1; i <= 500; i++)
     {
         for(var j = 1; j < 500; j++)
         {
             if(world[i][j])
             {
                 Instantiate (objects[world[i][j]], Vector3(i, j, 0), Quaternion.identity);
             }
         }
     }
     Debug.Log("done loading");
 }
 
 function Update () 
 {
     if(generate)
     {
         generate = false;
         GenerateWorld();
     }
     if(load)
     {
         load = false;
         GetWorldData();
         LoadWorld();
     }
 }
 
 function Start()
 {
     for (var i = 0; i < 500; i++)
     {
         world[i] = new Array(500);
     }
 }