title: Object not found error with ggplot2
body: <p>I can not get my head around this.</p>
  
  <p>These examples are working:</p>
  
  <pre><code># Function with geom_density
  
  gr.den &lt;- function(var.name) {
    ggplot(results, aes(get(var.name), fill = name)) +
    geom_density(alpha = 0.2) +
    geom_vline(xintercept = tv[, var.name], color="red", size=1) +
    xlab(var.name)
  }
  
  gr.den("sum.Empl")
  
  # Example with geom_point
  
  ggplot(results, aes(sum.All, sum.Empl)) +
    geom_point(alpha = 1/5) +
    opts(aspect.ratio = 1) +
    facet_grid(. ~ name)
  </code></pre>
  
  <p>Then I am trying to create similar function using geom_point:</p>
  
  <pre><code>gr.sc &lt;- function(var.name.1, var.name.2) {
    ggplot(results, aes(get(var.name.1), get(var.name.2))) +
    geom_point(alpha = 1/5) +
    opts(aspect.ratio = 1) +
    facet_grid(. ~ name)
  }
  
  gr.sc("sum.All", "sum.Empl")
  </code></pre>
  
  <p>And I am getting this error. Why?</p>
  
  <pre><code>Error in get(var.name.1) : object 'var.name.1' not found
  </code></pre>