How To Solve this Problem:a potentially dangerous request.form value was detected from the client...

1- added the following to the existing "page" directive in that .aspx file.
ValidateRequest="false"

2-add requestValidationMode="2.0" to the httpRuntime configuration section of the web.config file like the following:

 <httpRuntime requestValidationMode="2.0"/> 

How To Get Lookup ID,Name and EntityType in CRM 2011

First Write a function to get lookup

    function GetLookup(FieldName) {

    var lookup = Xrm.Page.data.entity.attributes.get(FieldName)

    if (lookup == null) { return null; };

    var lookupObj = lookup.getValue();

    return lookupObj[0];     

 }

1- To Get Lookup Id.

    function GetLookupId(fieldName) {

    var lookup = GetLookup(fieldName);

    if (lookup != null) {

        return lookup.id;

      }

    return null;

  }

2- To Get Lookup Name.

 function GetLookupName(fieldName) {

    var lookup = GetLookup(fieldName);

    if (lookup != null) {

        return lookup.name;

      }

    return null;

  }

3- To Get Lookup Entity Type. 

    function GetLookupEntityType(fieldName) {

    var lookup = GetLookup(fieldName);

    if (lookup != null) {

        return lookup.entityType;

      }

    return null;

  }

How to: Install and Uninstall Windows Services

* To  Install Or Uninstall Windows Services open Visual studio command Prompt and write this command

      Cd  D:\WindowsService\WindowsService\bin\Debug  
 (Path of WindowsService.exe) then.

1-To Install Windows Service write this Command

           installutil WindowsService.exe

2- To Uninstall Windows Service write this Command

          installutil /u  WindowsService.exe

Sql Server Error:A connection was successfully established with the server, but then an error occurred during the login proces

To Solve this Error do the following:

1-Open SQL Server Management Studio and login

2-From Server Name right click and Select properties

3-Select Security in left menu and set server authentication to SQL Server and Windows Authentication.

3-Stop SQl service(MSSQLSERVER) and Start it again.
4- Open SQL Server Management Studio. Do not login, cancel the login dialog.
5- From the file Menu select New->Database engine query, and login(windows Authentication).
6-Execute the query ALTER LOGIN sa WITH PASSWORD = ''; to reset the password (if the sa is not enabled then type ALTER LOGIN sa ENABLE to do so).
7-Login with the sa user and add the Administrator user.