Save values in code behind asp

Question

I have a aspx page. I have another class and stored procedure. From the aspx page I call a funtion (Term.ShowTerm()) and save data to txtInfo[]. I want to use that info (these variables) after a user reloads the page (a postback -> btnSymptoms_Click for example), but txtInfo resets its value. Is it possible somehow to save these value?

Part of the code:

public partial class dictionaryShowTerm : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
    if (!Page.IsPostBack)
    {
        Term.ShowTerm( txtInfo,SqlDataSource1.ConnectionString);
        lblInfoAboutCategory.Text = txtInfo[1];
    }
}

string[] txtInfo = new string[]
{
        "Description",
        "Symtoms",
        "Causes",
        "Treatment",
};

protected void btnSymptoms_Click(object sender, EventArgs e)
{
                lblInfoAboutCategory.Text = txtInfo[0];
}
}