bOpera = (navigator.userAgent.indexOf("Opera",0) != -1) ? 1 : 0 ;
bIE = ((navigator.appName.charAt(0) == "M") && (bOpera==0)) ? 1 : 0 ;
bNetscape = ((navigator.appName.charAt(0) == "N") && (bOpera==0)) ? 1 : 0 ;


var actT = 0;                                 

var TimeID;
var scrx,dx,x,inix,viewx;
var photo_num;
var now_photo = 1;
var scroll_width = 650;
var moving = 0;

	photo_num = 5;
        dx = 0;
        x = 0;
        inix = 0;
        viewx = inix;

function right(target_num){
	if(target_num){
		scrx = (target_num - now_photo) * scroll_width;
		now_photo = target_num;
	}else{
		if(now_photo == photo_num){
			scrx = 0;
		}else{
	       	 	scrx = scroll_width;
			now_photo += 1;
		}
	}
	viewx_amari = viewx % scroll_width;
	if(viewx_amari > 0){
		scrx += (scroll_width - viewx_amari);
	}
        inix = viewx;
        dx = 0;
        x = 0;
        scroll_right();
}

function left(target_num){
	if(target_num){
		scrx = (now_photo - target_num) * scroll_width;
		now_photo = target_num;
	}else{
		if(now_photo == 1){
			scrx = 0;
		}else{
			now_photo -= 1;
       		 	scrx = scroll_width;
		}
	}
	viewx_amari = viewx % scroll_width;
	if(viewx_amari > 0){
		scrx += (scroll_width - viewx_amari);
	}
        inix = viewx;
        dx = 0;
        x = 0;
        scroll_left();
}

function scroll_right(){
        var tgtx = inix - scrx;
        if( x < (scrx/2) ){
                dx++;
        }else if( x > (scrx/2) ){
                dx--;
                dx = Math.max(dx , 1);
        }
        x += dx;
        viewx = inix - x;
        viewx = Math.max( viewx , tgtx );
        document.getElementById('photolayer').style.left = viewx+'px';
        if(viewx <= tgtx){
                clearTimeout(TimeID);
		moving=0;
        }else{
                TimeID = setTimeout( "scroll_right()" , actT);
        }
}

function scroll_left(){
        var tgtx = inix + scrx;
        if( x < (scrx/2) ){
                dx++;
        }else if( x > (scrx/2) ){
                dx--;
                dx = Math.max(dx , 1);
        }
        x += dx;
        viewx = inix + x;
        viewx = Math.min( viewx , tgtx );
        document.getElementById('photolayer').style.left = viewx+'px';
        if(viewx >= tgtx){
                clearTimeout(TimeID);
		moving=0;
        }else{
                TimeID = setTimeout( "scroll_left()" , actT);
        }
}

function photoNum(num){
	if(moving == 1){
		return;
	}else{
		moving = 1;
	}
	if(num < now_photo){

		left(num);
	}else{
		right(num);
	}
}