Create a UIView with a black background that is 1 pixel high and 320 pixels wide?
For Example
For Horizontal Line
UIView *horizontalLine = [[UIView alloc]initWithFrame:CGRectMake(x cordinate,y cordinate,1,linelenth)];
horizontalLine.backgroundColor = [UIColor blackColor];
[self.view addSubview:horizontalLine];
[horizontalLine release];
For Vertical Line
UIView *verticalLine = [[UIView alloc]initWithFrame:CGRectMake(x cordinate,y cordinate,linelenth,1)];
verticalLine.backgroundColor = [UIColor blackColor];
[self.view addSubview:verticalLine];
[verticalLine release];