Problem with listbox in c#

[Abdelaziz_1]

Hey guys,now I have a listbox I need to add in it name of day and time and the program read each item in listbox auto and if the first item = my pc day and time show message and so on...
But I got dat error when the program reach the last item give me that error
And when I click on start button it doesnot wait until the first item = my pc day and time it go on the each item until reach the last give me that error

But It work in visual basic 100%

Any help in my codes

My codes:

http://imgur.com/dl0AwVt

In button add items to listbox code:

Listbox5.items.add(textbox1.text + textbox2.text)
Listbox5.selectesindex=0

in Button1 start timer code:

timer1.enabled=true;

in Timer1 code:

if (listbox5.text= datetime.now.tostring("ddd") + datetime.now.tolongtime())

Messagebox.show("done")
Listbox.selectedindex +=1

[pritaeas]

The error message indicates that the SelectedIndex is higher than the number of items in the listbox.

[Abdelaziz_1]

So what should I do ?