[1.4.7] OnItemUse Help

I'm trying to create a item that when you click on a certain block, it will change into a different block that you can collect. Here is my code so far:

public boolean onItemUse(ItemStack itemstack, EntityPlayer entityplayer, World world, int par4, int par5, int par6, int par7)
        {
                 if(world.getBlockId(par4, par5, par6) == ModpackExtras.minedawnoreblock.blockID)
                 {
    					 itemstack.damageItem(1, entityplayer);
                         entityplayer.inventory.addItemStackToInventory(new ItemStack(ModpackExtras.glowshardblock));
                         return true;
                 } else
                 {
                         return false;
                 }
        }

I set it to give you it instead of changing into the block for testing purposes. I went to try it, but it did not activate or do anything. I tried taking out the if statement to see if it was getting caught up on checking the block, but it did not work. Please help.