object enabled

For my game you will have to buy items but i cant figure out how to make it be like - You dont have a 'gun' or You have put on the Gun.

But even when i do this /wear rocket, it works when i havnt even bought the item.

so my question is, how can i get it so that the p rogram knows that i have one thing, and not the other item?

VB Code:

Private Sub TextBox1_KeyPress(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyPressEventArgs) Handles TextBox1.KeyPress
        If TextBox1.Text = "" And (Asc(e.KeyChar)) = 13 Then
            MsgBox("Need to type something")
        ElseIf TextBox1.Text = "/buy gun" Then
            chatwin.Text = chatwin.Text & vbCrLf & "You have bought a Paintball gun for $150"
            TextBox1.Clear()
        ElseIf TextBox1.Text = "/buy tube" Then
            chatwin.Text = chatwin.Text & vbCrLf & "You have bought a tube of paintballs for $30"
            TextBox1.Clear()
        ElseIf TextBox1.Text = "/wear gun" Then
            chatwin.Text = chatwin.Text & vbCrLf & "You have put on" & gun
            TextBox1.Clear()
 
        ElseIf (Asc(e.KeyChar)) = 13 Then
 
            chatwin.Text = chatwin.Text & vbCrLf & (UserName) & ":" & " " & TextBox1.Text
            TextBox1.Clear()
        End If
    End Sub

You should use a collection for the items that are available and another one for items that you have. Then before using an item you should see if it is in the collection of items you have.

so should i have like a list inventory and make it like
If ' ' ' = /buy gun then
linventory.items.add"gun"

or something like that right?

Also how can i make it so that if the item is not in the listbox(inventory) it will say "its not there" in other words how can i make the program check to see if there is an item on the person.?

Thanks