title: Error while Running a simple Shiny app
body: <p>I am trying to run a simple Shiny App that takes a couple of text inputs to generate an SQL statement.  I keep getting the following error when I have the textInput control uncommented.</p>
  
  <p>Error in match.arg(position) : 'arg' must be NULL or a character vector</p>
  
  <p>The code I am running is:
  <strong>ui.R</strong></p>
  
  <pre><code>library(shiny)
  
  shinyUI(fluidPage(
  
   # Application title
   titlePanel("SQL Developer"),
  
   # Sidebar with a slider input for number of bins
  sidebarLayout(
  sidebarPanel(
    sliderInput("topnrows",
                "Number of rows to show:",
                min = 1,
                max = 100,
                value = 50)
  ),
  
  textInput("text1", label = "Text input", value = "Enter text..."),
  # textInput("dbName",
  #           label="Enter the Database Name",
  #           value="Enter Database Name"),
  # textInput("tableName",
  #           "Enter the Table Name"),
  
  
  # Show a plot of the generated distribution
  mainPanel(
   h3( textOutput("sqlText"))
  )
  )
  ))
  </code></pre>
  
  <p><strong>server.R</strong>
      library(shiny)</p>
  
  <pre><code>shinyServer(function(input, output) {
  
  
   output$sqlText &lt;- renderPrint({
  
  
   paste("select top ", input$topnrows, " * from trial.table",sep='')
   })
  
   })
  </code></pre>
  
  <p>Commenting the textInput() lines, I can run the app.  I haven't been able to figure out what I was missing in the textInput function for the error to show up.  Any help is greatly appreciated.</p>