$(document).ready(function() {
	//slider functions

	var numItems = 4;
	var numClicks = 0;
	
	//sets the previous button to look disabled to begin with
	document.getElementById("sliderBack").style.color="#CCC";
	document.getElementById("sliderBack").style.backgroundColor="#BF9900";
	document.getElementById("sliderBack").style.borderColor="#DA0";
	
    // Start animation
	$("#sliderNext").click(function(){
	
		//unsets the back buttons disabled styles and moves the sliding div	
		if(numClicks < numItems-1){	
			$(".block").animate({left: '-=375px'}, 1500);
			document.getElementById("sliderBack").style.color="";
			document.getElementById("sliderBack").style.backgroundColor="";
			document.getElementById("sliderBack").style.borderColor="";	
			numClicks ++;
		}
		
		//sets the next button to look disabled once the last item has been reached
		if(numClicks == numItems-1){
			document.getElementById("sliderNext").style.color="#CCC";
			document.getElementById("sliderNext").style.backgroundColor="#BF9900";
			document.getElementById("sliderNext").style.borderColor="#DA0";
		}
	});
		
	// Start animation in the opposite direction
	$("#sliderBack").click(function(){
		
		//unsets the next buttons disabled styles and moves the sliding div
		if(numClicks > 0){	
			$(".block").animate({left: '+=375px'}, 1500);
			document.getElementById("sliderNext").style.color="";
			document.getElementById("sliderNext").style.backgroundColor="";
			document.getElementById("sliderNext").style.borderColor="";
			numClicks --;
		}
		
		//sets the back button to look disabled once the first item has been reached
		if(numClicks == 0){
			document.getElementById("sliderBack").style.color="#CCC";
			document.getElementById("sliderBack").style.backgroundColor="#BF9900";
			document.getElementById("sliderBack").style.borderColor="#DA0";
		}
	});
	
});