C# - Dropdownlist In Masterpage Value Not Updated After New Selected?

I have a dropdownlist implemented in my masterpage. It has an sql data source from which it loads the values of companies. Depending on which value(company) selected, it shows that value in a label on a different page. The ddl which is in the masterpage is ofc still visible and should display the selected value which it does at the 1st time a value is selected. But when i select another value in the ddl it shows the value which was 1st selected and so on. So it doesn't update or something.

My code:

This is the onselectedIndexChanged event handler:

protected void DropDownListType_SelectedIndexChanged(object sender, EventArgs e)
{
String input1 = DropDownListType.Text;
String input2 = DropDownListType.SelectedValue;
String url = "~/test.aspx?pcompany="+input1;
DropDownListType.SelectedValue = input2;
Session["Company"] = input2;
Response.Redirect(url);
}

and this is the code i'm using in my Page_load method from the masterpage:

if (Session["Company"] != null)
{
DropDownListType.SelectedValue = (String)Session["Company"];
}

If I remove this last piece of code from my page_load method it updates the label with value on the redirected page but it resets my ddl to default value instead of keeping it at 4 when value 4 selected.