title: A simple birth year calculator using Kotlin
body: <p>I start doing a simple android app for practice to calculate the age with Kotlin programming language, the error came from the line <code>34</code>, can someone help me with this and fix it to know where is my wrong because I am just very beginner</p>
  
  <pre><code>    package com.calcult.age.agecalcult
  
  import android.support.v7.app.AppCompatActivity
  import android.os.Bundle
  import android.widget.Toast
  import kotlinx.android.synthetic.main.activity_main.*
  import java.util.*
  
  class MainActivity : AppCompatActivity() {
  
      override fun onCreate(savedInstanceState: Bundle?) {
          super.onCreate(savedInstanceState)
          setContentView(R.layout.activity_main)
  
          var my_age_number =  ageText.text!!
          var my_month_number =  ageText2.text!!
          var my_day_number =  ageText3.text!!
          var calcult_age_button = doIT
  
       calcult_age_button.setOnClickListener {
  
           if(my_age_number.isEmpty()){
  
               Toast.makeText(this,"ادخل سنه ميلادك !",Toast.LENGTH_LONG).show()
           }else if (my_age_number.length &lt; 4 || my_age_number.length &gt; 4){
  
               Toast.makeText(this,"ادخل سنه ميلاديه صالحه الأستعمال !",Toast.LENGTH_LONG).show()
           }else if (my_age_number.length == 4){
  
               fun getAge(){
  
                  val get_the_year = Calendar.getInstance().get(Calendar.YEAR);
  
                   val calculat_the_age = my_age_number - get_the_year
  
  
               }
           }
  
       }
  
          }
  }
  </code></pre>