SqlParameter[] param = new SqlParameter[5];
string period = string.Empty, week = string.Empty;
param[0] = new SqlParameter("@param1", "value");
param[1] = new SqlParameter("@param2", "value");
param[2] = new SqlParameter("@param3", "value");
if(period == week)
{
param[3] = new SqlParameter("@startdate", "02/06/2012");
param[4] = new SqlParameter("@enddate", "02/11/2012");
}
else
{
param[3] = new SqlParameter("@startdate", DBNull.Value );
param[4] = new SqlParameter("@enddate", DBNull.Value);
}