function switch_rb_image(img_tag, bw) {
  if (!bw) {
    if (img_tag.src.lastIndexOf('_bw')) {
      img_tag.src = img_tag.src.substring(0, img_tag.src.lastIndexOf('_bw')) + '.png';
    }
  } else {
    if (img_tag.src.lastIndexOf('_bw') == -1) {
      img_tag.src = img_tag.src.substring(0, img_tag.src.lastIndexOf('.png')) + '_bw.png';
    }
  }
}

function hide_mail(el_id, pc1, pc2, pc3) {
  var el = document.getElementById(el_id);
  if (el) {
    mail = pc1 + '@' + pc2 + '.' + pc3;
    el.innerHTML = mail;
    el.href = 'mailto: ' + mail;
  }
}

function functionFocus(el){	
	//alert(el.innerHTML);
	if(el.innerHTML === "Vaše zpráva pro nás."){
		this.innerHTML = '';
	}
}