var text="Eugene Yevgen Oksai, Olesya, Yevgen";
myName="Yevgen";
hits=[];
for (i=0;i<=text.length;i++){
    if (text[i]==='Y'){
        for(j=i; j< (i+ myName.length);j++){
            hits.push(""+text[j]+"")}}    
        }
if (hits!=0){
        console.log(hits);}
        else console.log("Your name wasn`t found");

var text = "Eugene Yevgen Oksai, Olesya, Yevgen",
      myName = "Yevgen",
      hits = [];
  for (i = 0; i < text.length; i++) {
      if (text[i] === 'Y') {
          var str = '';
          for (j = i; j < (i + myName.length); j++) {
              str += text[j]
          };
          hits.push(str)
      }
  }

  if (hits.length) alert(hits);

var text = "Eugene Yevgen Oksai, Olesya, Yevgen",
      myName = /Yevgen/g;
      alert(text.match(myName));

var text = "Eugene Yevgen Oksai, Olesya, Yevgen",
      myName = /Yevgen/g;
      alert(text.match(myName));

myName = /Yevgen/g;

var legal_names = 'Eugene|Yevgen|Oksa|Olesya|Yevgen';

var reg = new RegExp('^(?:'+legal_names+')$');

var matched = 'Oksa'.match(reg);

console.log(matched); // Array['Oksa']

private static function is_input($name) {
		return preg_match('/^(?:button|checkbox|color|date|datetime|datetime-local|email|file|hidden|image|month|number|password|radio|range|reset|search|submit|tel|text|time|url|week)$/',$name);
	}