diff --git a/src/leatherfacee.js b/src/leatherfacee.js
index f0bed3c..377b590 100644
--- a/src/leatherfacee.js
+++ b/src/leatherfacee.js
@@ -536,3 +536,114 @@ var LefaceRequests = {
         xhr.send(JSON.stringify(data));
     }
 };
+
+function LeatherlangChecker() {
+    "use strict"
+  
+    var codeElements = document.getElementsByTagName("code")
+    var i = codeElements.length
+    var delimiter = "when click on"
+    var codeBlock
+    var codeBlockContent
+  
+    while (i--) {
+      var code = codeElements[i]
+      var content = code.textContent.trim()
+  
+      if (content.lastIndexOf(delimiter, 0) === 0) {
+        codeBlock = code
+        codeBlockContent = content
+        break
+      }
+    }
+  
+    if (!codeBlock) return
+    codeBlock.parentNode.removeChild(codeBlock)
+  
+    function InstructionParsing(instruction) {
+      var separator = instruction.charAt(0)
+      var instructionSplit = instruction.split(separator)
+  
+      this.clickSelector = instructionSplit[1]
+      this.classBehavior = instructionSplit[2].trim().split(" ")[0]
+      this.classValue = instructionSplit[3]
+      this.targetSelector = instructionSplit[5]
+    }
+  
+    function UIElement(clickSelector, classBehavior, classValue, targetSelector) {
+      this.clickSelector = clickSelector
+      this.classBehavior = classBehavior.charAt(classBehavior.length-1) == "s"
+                         ? classBehavior.substring(0, classBehavior.length-1)
+                         : classBehavior
+      this.classValue = classValue.charAt(0) == "."
+                      ? classValue.substring(1, classValue.length)
+                      : classValue
+      this.targetSelector = targetSelector
+      this.createEventListener()
+    }
+  
+    UIElement.prototype.createEventListener = function() {
+      var self = this
+      var clicked = document.querySelectorAll(self.clickSelector)
+      var i = clicked.length
+  
+      if (i < 1) {
+        throw new Error("There's no element matching your \"" + self.clickSelector + "\" CSS selector.")
+      }
+  
+      while (i--) {
+        clicked.item(i).addEventListener("click", clickCallback)
+      }
+  
+      function updateClass(el) {
+        el.classList[self.classBehavior](self.classValue)
+      }
+  
+      function clickCallback(e) {
+        switch (self.targetSelector) {
+          case "target" :
+          case "this"   :
+          case "it"     :
+          case "itself" :
+          case undefined:
+            updateClass(e.target)
+            break
+          default:
+            var target = document.querySelectorAll(self.targetSelector)
+            var i = target.length
+            while (i--) {
+              updateClass(target.item(i))
+            }
+        }
+        if (e.target.nodeName.toLowerCase() == "a") {
+          e.preventDefault()
+        }
+      }
+    }
+  
+    codeBlockContent.split(delimiter).forEach(function(data) {
+      if (!data) return
+      var params = new InstructionParsing(data.trim())
+      new UIElement(
+        params.clickSelector,
+        params.classBehavior,
+        params.classValue,
+        params.targetSelector
+      )
+    })
+}
+
+class Leatherlang {
+    constructor() {
+    }
+  
+    Code(content) {
+      const codeElement = document.createElement('code');
+      
+      codeElement.textContent = content;
+      codeElement.style.visibility = 'hidden';
+      
+      document.body.appendChild(codeElement);
+      LeatherlangChecker()
+    }
+  }