var imageFlag=0
var max=2
var images1=new Array()
images1[0]="111topography.jpg"
images1[1]="111climate.jpg"
images1[2]="111cities.jpg"

function next()
{
 
 imageFlag+=1
if(imageFlag>max){imageFlag=0}

 document.palestine.src=images1[imageFlag]
                
}

 
function previous()
{

imageFlag -=1
if(imageFlag<0){imageFlag=max}   
document.palestine.src=images1[imageFlag]
              
        
}