diff --git a/content_scripts/fairlang.js b/content_scripts/fairlang.js
index a577c7b..573df6c 100644
--- a/content_scripts/fairlang.js
+++ b/content_scripts/fairlang.js
@@ -2,6 +2,12 @@
 // Content script to be run on pages
 // ---------------------------------
 
+function checkTextarea(textarea) {
+	console.log("click " + textarea.id + " -> " + textarea.value);
+
+	// TODO make queries to the fairlanguage server
+}
+
 (function() {
 	// Only run this script once
 	if (window.hasRun) {
@@ -11,9 +17,21 @@
 
 	// Search for all text areas
 	document.querySelectorAll("textarea").forEach(function(textarea) {
-		// Do something with it...
-		console.log(textarea);
+		// for testing: highlight textarea with red border
+		// TODO
 		textarea.style.border = "2px solid red";
-	});
 
+		// Create a "Check fairness" button which is placed next to the textarea
+		// TODO image button integrated into the textarea...
+		var buttonCheck = document.createElement("button");
+		buttonCheck.textContent = "Check fairness!";
+
+		// Add click event listener
+		buttonCheck.addEventListener("click", (e) => {
+			checkTextarea(textarea);
+		});
+
+		// Append button to the textarea
+		textarea.after(buttonCheck);
+	});
 })();