#1 NULL Parameter

[Couchkartoffel]

running on Win7 x64
here are the exceptiondetails
if you need a translation of the german parts, just ask

************** Ausnahmetext **************
System.ArgumentNullException: Der Wert darf nicht NULL sein.
Parametername: format
bei System.Drawing.Image.Save(String filename, ImageFormat format)
bei Batch_Image_Resizer.Form1.cmdResize_Click(Object sender, EventArgs e)
bei System.Windows.Forms.Control.OnClick(EventArgs e)
bei System.Windows.Forms.Button.OnClick(EventArgs e)
bei System.Windows.Forms.Button.OnMouseUp(MouseEventArgs mevent)
bei System.Windows.Forms.Control.WmMouseUp(Message& m, MouseButtons button, Int32 clicks)
bei System.Windows.Forms.Control.WndProc(Message& m)
bei System.Windows.Forms.ButtonBase.WndProc(Message& m)
bei System.Windows.Forms.Button.WndProc(Message& m)
bei System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m)
bei System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m)
bei System.Windows.Forms.NativeWindow.Callback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)

************** Geladene Assemblys **************
mscorlib
Assembly-Version: 2.0.0.0.
Win32-Version: 2.0.50727.4952 (win7RTMGDR.050727-4900).
CodeBase: file:///C:/Windows/Microsoft.NET/Framework/v2.0.50727/mscorlib.dll.
----------------------------------------
Batch Image Resizer
Assembly-Version: 1.0.3656.37367.
Win32-Version: 1.0.3656.37367.
CodeBase: file:///D:/Downloads/Batch%20Image%20Resizer.exe.
----------------------------------------
System.Windows.Forms
Assembly-Version: 2.0.0.0.
Win32-Version: 2.0.50727.4927 (NetFXspW7.050727-4900).
CodeBase: file:///C:/Windows/assembly/GAC_MSIL/System.Windows.Forms/2.0.0.0__b77a5c561934e089/System.Windows.Forms.dll.
----------------------------------------
System
Assembly-Version: 2.0.0.0.
Win32-Version: 2.0.50727.4927 (NetFXspW7.050727-4900).
CodeBase: file:///C:/Windows/assembly/GAC_MSIL/System/2.0.0.0__b77a5c561934e089/System.dll.
----------------------------------------
System.Drawing
Assembly-Version: 2.0.0.0.
Win32-Version: 2.0.50727.4927 (NetFXspW7.050727-4900).
CodeBase: file:///C:/Windows/assembly/GAC_MSIL/System.Drawing/2.0.0.0__b03f5f7f11d50a3a/System.Drawing.dll.
----------------------------------------
Microsoft.VisualBasic
Assembly-Version: 8.0.0.0.
Win32-Version: 8.0.50727.4927 (NetFXspW7.050727-4900).
CodeBase: file:///C:/Windows/assembly/GAC_MSIL/Microsoft.VisualBasic/8.0.0.0__b03f5f7f11d50a3a/Microsoft.VisualBasic.dll.
----------------------------------------
mscorlib.resources
Assembly-Version: 2.0.0.0.
Win32-Version: 2.0.50727.4952 (win7RTMGDR.050727-4900).
CodeBase: file:///C:/Windows/Microsoft.NET/Framework/v2.0.50727/mscorlib.dll.
----------------------------------------
System.Windows.Forms.resources
Assembly-Version: 2.0.0.0.
Win32-Version: 2.0.50727.4927 (NetFXspW7.050727-4900).
CodeBase: file:///C:/Windows/assembly/GAC_MSIL/System.Windows.Forms.resources/2.0.0.0_de_b77a5c561934e089/System.Windows.Forms.resources.dll.
----------------------------------------