title: I would like to know how to link 2 or more Combobox values
body: <p>I would like to know how to link 2 or more Combobox values,
  Example; </p>
  
  <p>I have <strong>jcombobox1</strong> with values <strong>room1</strong> and <strong>room2</strong> with items <strong>bed1</strong>, <strong>bed2</strong> and <strong>bed3</strong> 
  The question is, lets say I run my program and select <strong>room1</strong> and <strong>bed2</strong> then click save, this two values will be added to my database, and when i go back to select <strong>room1</strong> again, <strong>bed2</strong> should be cleared from <strong>jcombobox2</strong> and so will the same apply to <strong>bed1</strong> and <strong>bed3</strong> when i do the same save action.</p>
  
  <p>when I come to select <strong>room2</strong>, it should have <strong>bed1</strong>,<strong>bed2</strong> and <strong>bed3</strong> readily available to be selected.</p>
  
  <p>I would appreciate a method to link <strong>jcombobox1</strong> items with <strong>jcombobox2</strong> items separately, without one affecting values of the other.</p>