Search ListItem in the SharePoint List using Server Side Code

Note:- Here Title is the Primary Key.

if (txtUserName.Text != "")

{

       SPWeb currentWeb = SPContext.Current.Web;

       SPList lstLogin = currentWeb.Lists["Login"];

       SPQuery sQuery = new SPQuery();

       sQuery.Query = "<Where><Eq><FieldRef Name='UserName' /><Value

       Type='Text'>" + txtUserName.Text.ToString().ToLower() + "</Value></Eq></Where>";

       SPListItemCollection myColl = lstLogin.GetItems(sQuery);

       if (myColl.Count > 0)

       {

              SPListItem item = myColl[0];

              txtPassWord.Text = item["PassWord"].ToString();

       lblMessage.Text = "Record Found " + txtUserName.Text;

       }

}