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An error related to the network or specific instance occurred while establishing a connection to SQL

Server. The server is not found or is not accessible. Verify that the instance name is

correct and that SQL Server is configured to allow remote connections.

(provider: SQL Network Interfaces, error: 26 - Error locating server / instance of the specified)

  [color= #000000; font-weight: bold;]public partial [color= #000000; font-weight: bold;]class Default_master [color= #339933;]: [color= #990000;]System[color= #339933;].Web[color= #339933;].UI[color= #339933;].MasterPage [color= #009900;]{         protected void Page_
Load[color= #009900;](object sender[color= #339933;], EventArgs e[color= #009900;])     [color= #009900;]{               [color= #b1b100;]if [color= #009900;]([color= #009900;](cEmployee[color= #009900;])[color= #009900;](Session[color= #009900;][[color= #0000ff;]"Employee"[color= #009900;]][color= #009900;]) [color= #339933;]!= nu
ll[color= #009900;])          [color= #009900;]{             Lb_Employee[color= #339933;].Text [color= #339933;]=[color= #0000ff;]" Bienvenue :  " [color= #339933;]+ [color= #009900;]([color= #009900;](cEmployee[color= #009900;])[color= #009900;](Session[color= #009900;][[color= #0000ff;]"Employee"
[color= #009900;]][color= #009900;])[color= #009900;])[color= #339933;].Name[color= #339933;].ToString[color= #009900;]([color= #009900;])[color= #339933;];           [color= #009900;]}     [color= #009900;]}       protected void SousMenu1_MenuItemClick[color= #009900;](object send
er[color= #339933;], MenuEventArgs e[color= #009900;])     [color= #009900;]{       [color= #009900;]}     protected void SousMenu1_MenuItemClick1[color= #009900;](object sender[color= #339933;], M
enuEventArgs e[color= #009900;])     [color= #009900;]{       [color= #009900;]}     protected void LinkButton1_Click[color= #009900;](object sender[color= #339933;], EventArgs e[color= #009900;]) 
    [color= #009900;]{         Server[color= #339933;].Transfer[color= #009900;]([color= #0000ff;]"Default.aspx?action=logout"[color= #009900;])[color= #339933;];     [color= #009900;]} [color= #009900;]}