Multiple upload of images into one folder

Hi i have 4 textboxes in which a user can add an image, however my problem is on how to insert each image into the same folder and assign the SAME uniqueID/FK to each one, this is the code i have so far, also what should i use, because as it is now, i have just 4 textboxes, and my problem is in how to loop through each one, bearing in mind i am not using a repeater or grid. Please advise me on the best way to achieve this

  protected void Button1_Click(object sender, EventArgs e)

{
int USERALBUMINFO_ID = (int)Session["USERALBUMINFO_ID"];
// Initialize variables

///CODE REMOVED FOR BREVITY

// Displaying success information
lblOutput.Text = "File uploade ...