title: Cannot insert explicit value for identity column in table 'IncomeTable' when IDENTITY_INSERT is set to OFF
body: <p>I set status of primary key in table to IDENTITY . I insert another fields of table in VS but when i run this program, the program has error. Why? What is my problem?</p>
  
  <p>ID field in my table is set Identity.</p>
  
  <p>The runtime error is: </p>
  
  <pre><code>Cannot insert explicit value for identity column in table 'IncomeTable' when IDENTITY_INSERT is set to OFF. 
  </code></pre>
  
  <p>in VS:</p>
  
  <pre><code>private void button1_Click(object sender, EventArgs e)
  {
      IncomeTable income = new IncomeTable();
      income.amount_income = amount;
      income.comment_income = comment;
      income.date_income = date;
      context.IncomeTables.InsertOnSubmit(income);
      context.SubmitChanges();
  }
  </code></pre>
  
  <p>I search but i cant solve this problem.
  Cheers</p>