diff --git a/report.html b/report.html
index 79b2b00..486b0f6 100644
--- a/report.html
+++ b/report.html
@@ -1544,6 +1544,12 @@ and adapted</em></p>
   uniqv[which(x == max(x))]
 }</code></pre>
 </div>
+<div id="remove-na" class="section level2" number="2.3">
+<h2><span class="header-section-number">2.3</span> Remove NA</h2>
+<pre class="r"><code>removeNA &lt;- function(d){
+  return(d[!is.na(d)])
+}</code></pre>
+</div>
 </div>
 <div id="load-data" class="section level1" number="3">
 <h1><span class="header-section-number">3</span> Load Data</h1>
@@ -2392,9 +2398,8 @@ gibt.</p>
 <div id="selbststudium-2.1" class="section level1" number="6">
 <h1><span class="header-section-number">6</span> Selbststudium 2.1</h1>
 <p>We have the year 2021 ## Preparation</p>
-<pre class="r"><code>birthyears &lt;- litdata$D7
-# remove NAs
-birthyears &lt;- birthyears[!is.na(birthyears)]
+<pre class="r"><code># remove NAs
+birthyears &lt;- removeNA(litdata$D7)
 age &lt;- 2021 - birthyears</code></pre>
 <div id="frequency" class="section level2" number="6.1">
 <h2><span class="header-section-number">6.1</span> Frequency</h2>
diff --git a/report.rmd b/report.rmd
index 6e61382..adb60b6 100644
--- a/report.rmd
+++ b/report.rmd
@@ -71,6 +71,15 @@ getmode <- function(v) {
 }
 ```
 
+## Remove NA
+```{r}
+removeNA <- function(d){
+  return(d[!is.na(d)])
+}
+```
+
+
+
 # Load Data
 ## Load from CSV
 ``` {r loadData}
@@ -352,9 +361,8 @@ displayFunction1(litdata, "D8")
 We have the year 2021
 ## Preparation
 ```{r}
-birthyears <- litdata$D7
 # remove NAs
-birthyears <- birthyears[!is.na(birthyears)]
+birthyears <- removeNA(litdata$D7)
 age <- 2021 - birthyears
 ```