function checkAtt() {
  if (document.getElementById('file').value != "") {
    var ext_file = document.getElementById('file').value;
    ext_file = ext_file.substring(ext_file.length-3,ext_file.length);
    ext_file = ext_file.toLowerCase();
    if	(ext_file != 'doc' && ext_file != 'xls' && ext_file != 'zip' && ext_file != 'rtf' && ext_file != 'pdf' && ext_file != 'jpg') {
      alert('Systém podporuje pouze tyto formáty (*.jpg, *.doc, *xls, *.rtf, *.pdf, *.zip).');
      return false; 
    }
  }
  if(document.getElementById('file').value == ''){
	alert('Nebyla vybrána žádná příloha.');
	return false; 
  }
}

function checkAttEdit() {
  if (document.getElementById('file').value != "") {
    var ext_file = document.getElementById('file').value;
    ext_file = ext_file.substring(ext_file.length-3,ext_file.length);
    ext_file = ext_file.toLowerCase();
    if	(ext_file != 'doc' && ext_file != 'xls' && ext_file != 'zip' && ext_file != 'rtf' && ext_file != 'pdf' && ext_file != 'jpg') {
      alert('Systém podporuje pouze tyto formáty (*.jpg, *.doc, *xls, *.rtf, *.pdf, *.zip).');
      return false; 
    }
  }
}

function checkPhotos() {
  if (document.getElementById('file').value != "") {
    var ext_file = document.getElementById('file').value;
    ext_file = ext_file.substring(ext_file.length-3,ext_file.length);
    ext_file = ext_file.toLowerCase();
    if	(ext_file != 'jpg') {
      alert('Systém podporuje pouze tyto formáty (*.jpg).');
      return false; 
    }
  }
  if(document.getElementById('file').value == ''){
	alert('Nebyla vybrána žádná fotografie.');
	return false; 
  }
}

function checkForBlur(f, puvodni){
  if (f.value.replace(/^\s+|\s+$/, '') == ''){
    f.value = puvodni
  }
}