Change Vertical and Horizontal ScrollBarHeight

public partial class Form1 : Form    
{
    const int LB_GETHORIZONTALEXTENT = 0x0193;   
    const int LB_SETHORIZONTALEXTENT = 0x0194;    
    const long WS_HSCROLL = 0x00100000L;    
    const int SWP_FRAMECHANGED = 0x0020;   
    const int SWP_NOMOVE = 0x0002;   
    const int SWP_NOSIZE = 0x0001;   
    const int SWP_NOZORDER = 0x0004;    
    const int GWL_STYLE = (-16);        

    public Form1()       
    {          
        InitializeComponent();      
        checkedListBox1.HorizontalScrollbar = true;      
        AddStyle(checkedListBox1.Handle, (uint)WS_HSCROLL);  
        SendMessage(checkedListBox1.Handle, LB_SETHORIZONTALEXTENT, 1000, 0);   
    }

    [DllImport("user32.dll")]
    static extern int SendMessage(IntPtr hwnd, int msg, int wParam, int lParam);        

    [DllImport("user32.dll")]       
    static extern uint GetWindowLong(IntPtr hwnd, int index);        

    [DllImport("user32.dll")]   
    static extern void SetWindowLong(IntPtr hwnd, int index, uint value);    

    [DllImport("user32.dll")]   
    static extern bool SetWindowPos(IntPtr hWnd, IntPtr hWndInsertAfter, int X, int Y, int cx, int cy, uint uFlags);    

     private void AddStyle(IntPtr handle, uint addStyle)   
    {
        // Get current window style          
        uint windowStyle = GetWindowLong(handle, GWL_STYLE);       

        // Modify style          
        SetWindowLong(handle, GWL_STYLE, windowStyle | addStyle);           

        // Let the window know of the changes  
        SetWindowPos(handle, IntPtr.Zero, 0, 0, 0, 0, SWP_NOMOVE | SWP_NOZORDER | SWP_NOSIZE | SWP_FRAMECHANGED);   
    }    
}