function random_img(){

	var rn = Math.floor(Math.random()*image.length)
	  if (rn == 0){
	     rn = 1;
	  }
	     return rn;
	     
}
	
	var image=new Array()
  	//specify random images below.
  	image[1] = "http://sgcity.org/parks/assets/images/random/2450East_1.jpg";
	image[2] = "http://sgcity.org/parks/assets/images/random/bluff1.jpg";
	image[3] = "http://sgcity.org/parks/assets/images/random/cox1.jpg";
	image[4] = "http://sgcity.org/parks/assets/images/random/ps_parks_01.jpg";
	image[5] = "http://sgcity.org/parks/assets/images/random/Town_Square.jpg";
	
	

//run this function on window.onload
function runPhotoLoad(){
	//run function
	var rn = random_img();
	//display image
	document.getElementById("middle_image").innerHTML = '<img src="' + image[rn] +'">';
}