function vowel_count(str1)  
{  
  var vowel_list = 'aeiouAEIOU';  
  var vcount = 0;  
    
  for(var x = 0; x < str1.length ; x++)  
  {  
    if (vowel_list.indexOf(str1[x]) !== -1)  
    {  
      vcount += 1;  
    }  
    
  }  
  return vcount;  
}  
console.log(vowel_count("The quick brown fox"));