function checkErr(form){
    var res= true;
    document.getElementById("errBox").innerHTML="";
    if(!form.Title.value.length){
	errMsg = "cannot be empty";
	displayErr(errMsg,form.Title);
	res= false;
    }else{
	displayOK(form.Title);
    }
    if(!form.Authors.value.length){
	errMsg = "cannot be empty";
	displayErr(errMsg,form.Authors);
	res= false;
    }else if(!form.Authors.value.match(/[A-Za-z]+/)){
	errMsg ="invalid (e.g. John D. and Me)";
	displayErr(errMsg,form.Authors);
	res = false;
    }else{
	displayOK(form.Authors);
    }
    if(!form.Abstract.value.length){
	errMsg = "cannot be empty";
	displayErr(errMsg,form.Abstract);
	res= false;
    }else{
	displayOK(form.Abstract);
    }
    if(!form.Reference.value.length){
	errMsg = "cannot be empty";
	displayErr(errMsg,form.Reference);
	res= false;
    }else{
	displayOK(form.Reference);
    }
    if(form.Link.value.length){
	if(!form.Link.value.match(/[A-Za-z]+p:\/\/([\w-_]+\.)+[\w-]+\w(\s*$|\/.*)/)){
	    errMsg = "invalid (e.g. http://www.domain.com/paper)";
	    displayErr(errMsg,form.Link);
	    res= false;
	}
    }else{
	displayOK(form.Link);
    }
    return res;
}

function displayErr(errMsg,element){
    element.style.border="1px solid red";
    var errBox =  document.getElementById("errBox");
    errBox.style.fontSize = "0.8em";
    //errBox.appendChild(document.createTextNode(errMsg));
    errBox.innerHTML += element.name+":"+errMsg+"<br/>";
}

function displayOK(element){
    element.style.border="1px solid #777";
}