title: java.util.IllegalFormatConversionException: f != java.lang.String Error
body: <pre><code>import javax.swing.JOptionPane;
  
  public class Minutes {
  
      public static void main(String[] args) {
          double  BasePlanCost = 20;
          final double BaseCostPerMinute=0.15;
  
          double MinutesUsed = Double.parseDouble(JOptionPane.showInputDialog("Please enter the amount of minutes Used: "));
          double CostForMinutes = BaseCostPerMinute * MinutesUsed;
          double GrandTotal = BasePlanCost + CostForMinutes;
          JOptionPane.showMessageDialog(null, String.format("$%.2f","**IST Wireless Receipt**","\n","Base Plan Cost:" +BasePlanCost,"/n","Cost For Minutes Used: "+ CostForMinutes,"/n","Grand Total :" +GrandTotal));
  
      }
  
  }
  </code></pre>
  
  <p>This program inputs the amount of minutes the user enters and calculates the grand total by adding the CostForMinutes and BasePlanCost. 
  CostForMinutes is calculated by multiplying the minutes the user enters and the BaseCostPerMinute. The out is all the numbers outputted by two decimal places and outputted as a receipt. </p>
  
  <p>When I compile the program it lets me input the amount of minutes but the code collapses and gives me this error </p>
  
  <pre><code>exception in thread "main" java.util.IllegalFormatConversionException: f != java.lang.String
  </code></pre>
  
  <p>can anyone help me out?</p>
  
  <p>EDIT this is what I want the output to look like
    <a href="http://i.stack.imgur.com/CubfC.png" rel="noreferrer">http://i.stack.imgur.com/CubfC.png</a></p>