Checking if user belongs to a group

Scenario:
Often we need to do some action depending upon as if user is part of certain sharepoint group or not.

Solution:
Simple function did the trick

Code:

public bool DoesUserExistInGroup(SPWeb web, SPUser user,string groupName)
{
      //Retrieving all the user groups in the site/web
      SPGroupCollection userGroups = user.Groups;

      foreach (SPGroup group in userGroups)
      {
         //Checking the group
         if (group.Name.Contains(groupName))
         {
             return true;
         } 
       }
            return false;
 }