function checkForm(authors){
  var f = document.abstracts;
  
  if(document.getElementById("a[]").options.length == 0){
    alert("Please enter at least one author");
    f.AU.focus();
    return false;  
  }
  if (f.CE.value == "" || f.CE.value.indexOf('@',0) == -1 || f.CE.value.length < 7 || f.CE.value.indexOf('.',0) == -1) {
    alert("Please fill in a valid email address");
    f.CE.focus();
    return false;
  }
  if (!document.getElementById("t1").checked && !document.getElementById("t2").checked) {
    alert("Please check a type value");
    document.getElementById("t1").focus();
    return false;
  }
  if (!document.getElementById("s1").checked && !document.getElementById("s2").checked && !document.getElementById("s3").checked) {
    alert("Please check a status value");
    document.getElementById("s1").focus();
    return false;
  }
  if (!document.getElementById("m1").checked && !document.getElementById("m2").checked) {
    alert("Please check a method");
    document.getElementById("m1").focus();
    return false;
  }
  if (f.Title.value==""){
    alert("Please fill in the Title");
    f.Title.focus();
    return false;
  }
  if (f.Abstract.value==""){
    alert("Please fill in the Abstract");
    f.Abstract.focus();
    return false;
  }
  
  for(j=0;j<authors.length;j++){
    var s=document.getElementById(authors[j]);
    for(i=0;i<s.options.length;i++)
      s.options[i].selected=1;
  }
  return true;
}

function removeOption(id){
  var x=document.getElementById(id);
  x.remove(x.selectedIndex);
}

function addOption(idau,idaf,idselect){
  var au=document.getElementById(idau);
  var af=document.getElementById(idaf);
  if(au.value=="" || af.value==""){
    alert("Author and Affiliation fields must be filled");
    return;
  }  
  var s=document.getElementById(idselect);
  var text=au.value+" - "+af.value;
  s.options.add(new Option(text,text));
  au.value="";
  af.value="";  
}