Hoping someone can guide an C# newbie. I'm looping through an array, and I want to add each element to a listbox on the form. But for each item, I want to preference it with the element name/number. I can't get past the compiler error with the code below, but if I remove the ctext="PID:" += i.ToString(); line it does add the text of the array item to the listbox.

PID:1 element 1 text
PID:2 element 2 text 
...

            string[] PID_Data = PIDString.Split(fieldSplitter);
            // Loop through each item and add to listbox
            string ctext = String.Empty;
            for(int i=0;i<PID_Data.Length;i++)
            {
                ctext = "PID: " += i.ToString();
                ctext += PID_Data[i];
                listBox1.Items.Add(ctext);
                ctext = String.Empty;
            }