ActionScript: getFirstIndex Function (For Ranges)

ranges.as

/**
* For Ranges
*/
function getFirstIndex(indexSelected:Number, range:Number, total:Number):Number
{
	var middle:Number = Math.ceil(range/2);
	var index:Number;
	
	if(indexSelected < middle)
		index = 1;
	else if( indexSelected > total - middle )
		index = total - range + 1;
	else
		index = indexSelected - middle + 1;
	
	return index;
}

trace( getFirstIndex(5,7,10) );