title: Simple Jframe with a combobox and a textfield and a result in a label
body: <p>I am a Java newbie so this question maybe foolish for some. I am using Eclipse with the swing window builder, but i can't figure out how to make my Jframe work.</p>
  
  <p>What i want to achieve is rather simple. </p>
  
  <ol>
  <li>I want a combobox with a number of options (lateron two columns, but i start with one), representing a bankcode.</li>
  <li>A textbox for entering a bankaccountnumber.</li>
  <li>a button that needs to use the selected value from the box and the accountnumber from the textbox to call a method createIban(code,number).
  This method returns a String with the full IBAN.</li>
  </ol>
  
  <p>I want this string presented in a label or something (maybe also copied to the clipboard or some).</p>
  
  <p>I hope someone can help me to get further in this quest.</p>