library(shiny)
shinyUI(pageWithSidebar(
  headerPanel("Hallo Welt Histogramm!"),
  sidebarPanel(
    sliderInput("obs", 
                "obs:", 
                min = 1,
                max = 1000, 
                value = 500)
  ),
  mainPanel(
    plotOutput("distPlot")
  )
))