// Keyboard Navigation

function setupKeyboardNav(){
	if (document.addEventListener) {
    	document.addEventListener("keydown",keydown,false);
    } else if (document.attachEvent) {
    	document.attachEvent("onkeydown", keydown);
    } else {
    	document.onkeydown= keydown;
    }
}


function keydown(e) {
	var keyCode = e.charCode ? e.charCode : e.keyCode;
	//alert(keyCode);
	if (keyCode>= 37 && keyCode <= 40) {
		if(prevBox) {
			var r = prevBox.row;
			var c = prevBox.col;
			switch(keyCode) {
				case 37:	c--;	break;	//left
				case 38:	r--;	break;	//up
				case 39:	c++;	break;	//right
				case 40:	r++;	break;	//down
			}
			
			if (r>=-1 && r<=rows && c>=-1 && c<=cols ) {
				if(c==cols) { 
					c = 0; r++;
				} else if(c==-1) { 
					c=cols-1; r--; 
				} else if(r==rows) { 
					r = 0; c++; 
				} else if(r==-1) {
					r=rows-1; c--;
				}
			} else if (r== rows || c==cols) {
				if(c==-1) { c = cols-1; r--;
				} else if(r==-1) { r = rows-1; c--; }
			}
			
			if ( r>=0 && r<rows && c>=0 && c<cols) {
				var id = c*rows+r;
				var box = document.getElementById("box"+id);
				if(box) scaleBox(box,false);
			}
		} else {
			var box = document.getElementById("box0");
			scaleBox(box,false);
		}
	} else if(open && prevBox) {
		switch(keyCode) {
			case 13: scaleBox(prevBox,false); break;	//escape
			case 27: scaleBox(prevBox,false); break;	//enter
			case 73: showInfo(prevBox.cid); // i
		}
	}
}