title: Subtract two variable
body: <p>I am designing my reports using Jasper reports, I have an income expense report where I am getting total Income using a variable <code>TOT_INCOME</code> and total Expenses using a second variable, <code>TOT_EXPENSES</code>. I need to Subtract the two variable to get the Net Profit.
  So I have Created a third Variable <code>TOT_PROFIT</code>. I am trying to get the Difference this way. On the third Variable Variable Expresion, I have:</p>
  
  <pre><code>$V{TOT_INCOME}-$V{TOT_EXPENSE}
  </code></pre>
  
  <p>as My expression. I am getting a wrong output. For example I have this Output:</p>
  
  <pre><code>TOTAL_INCOME  TOTAL_EXPENSES   PROFIT
  215,762.00    16,012.00        1,587,228.00
  </code></pre>
  
  <p>Which is clearly Wrong as <code>215,762.00-16,012 = 199,750.00</code>. All my values are doubles. On the Third Variable, my calculation is <code>sum</code>. Please Help where I might be doing a Mistake.</p>