Failed to update database LAKSHDB.MDF because the database is read-only.

i have hosted a website with database using windows server

when i run normal pages are running the data stored are being fethched and can be seen but for edit,save and delete button it gives error below

Failed to update database "C:\HOSTINGSPACES\RWTINDIA\RWTINDIA.COM\WWWROOT\APP_DATA\LAKSH_DB.MDF" because the database is read-only.

Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.  Exception Details: System.Data.SqlClient.SqlException: Failed to update database "C:\HOSTINGSPACES\RWTINDIA\RWTINDIA.COM\WWWROOT\APP_DATA\LAKSH_DB.MDF" because the database is read-only. Source Error: 

Line 46: 
Line 47:         SqlCommand cmd = new SqlCommand(qry, conn);
Line 48: cmd.ExecuteNonQuery(); Line 49: 
Line 50: 

Source File: c:\HostingSpaces\rwtindia\rwtindia.com\wwwroot\Principal.aspx.cs    Line: 48 

please help me .....

what i do?

i have checked all the folders and its properties all folders have all rights then also it is giving error