var NS4=(navigator.appName=="Netscape") && (parseInt(navigator.appVersion)<5); 

function maxlength(element, maxvalue){
    var q = eval("document.doierrorcatcher."+element+".value.length");
    var r = q - maxvalue;
    var msg = "Sorry, you have input "+q+" characters into the "+
       "text area box you just completed. It can return no more than "+
       maxvalue+" characters to be processed. Please abbreviate "+
       "your text by at least "+r+" characters";
    if (q > maxvalue){ 
        alert(msg);
        return false;
    }
    return true;
}

function setAction(action){
    if(action=='submit'){
        var errors = "";
        if(document.doierrorcatcher.missingHandle.value.length <=0 ){
            errors += "*  DOI must be provided.\n";
        }
    if(document.doierrorcatcher.userEmailAddress.value.length > 0){
	var x = document.doierrorcatcher.userEmailAddress.value;
	var filter  = /^([a-zA-Z0-9_\.\-])+\@(([a-zA-Z0-9\-])+\.)+([a-zA-Z0-9]{2,4})$/;
	if (! filter.test(x)){
            requiredfields += "\n   *  Incorrect email address format (someone@somedomain.com)\n";
            if(document.doierrorcatcher.userEmailAddress.value.indexOf('@') > 0){
                for (var i=0; i < document.doierrorcatcher.userEmailAddress.value.length; i++) {
                    var letter = document.doierrorcatcher.userEmailAddress.value.charAt(i).toLowerCase();
                    if (validchars.indexOf(letter) != -1)
                        continue;
                    requiredfields += "\n   *  Your email address contains an invalid character " + letter + ".\n";
                }
            }
        }
    }
    else{
//        requiredfields += "\n   *  Your Email address must be provided";
    }

        if(document.doierrorcatcher.referringPage.value.length <=0 ){
//            errors += "*  Referring Page must be provided.\n";
        }
        if(document.doierrorcatcher.comments.value.length <=0 ){
//            errors += "*  Comments must be provided.\n";
        }
        if(maxlength('comments',1020)){
        }else{
            errors += "*  Comments must be no more 1020 bytes.\n";
        }
        if(errors.length > 0){
            alert(errors);
        }else{
            return document.doierrorcatcher.submit();
        }
    }
}

function submitform(){
            return false;
}

function submit_check(){
        alert("submit_check");

    var requiredfields = "";
    if(maxlength('comments',1020)){
        return true;
    }
    else{
        return false;
    }
}

/////////////////////////////////////////
// Div Hide/Show functions
////////////////////////////////////////
function hideMenu (MenuName){
  if (NS4){
    eval('document.layers.'+MenuName+'.display="none"'); 
  } else {
    eval('document.getElementById(\''+MenuName+'\').style.display="none"');
  }
}

function showMenu (MenuName){
 if (NS4){
    eval('document.layers.'+MenuName+'.display="block"'); 
  } else {
    eval('document.getElementById(\''+MenuName+'\').style.display="block"'); 
  }
}

function toggleMenu(MenuName){
  if (NS4){
    eval('Shown=document.layers.'+MenuName+'.display;'); 
  } else {
    eval('Shown=document.getElementById(\''+MenuName+'\').style.display;'); 
  }
  
  if (Shown=="none"){
    showMenu(MenuName);
  } else {
    hideMenu(MenuName);
  }
}

function blackrule() {
    document.writeln('<table border="0" cellpadding="0" cellspacing="0" width="100%"><tr><td background="http://www.crossref.org/images/blackdottedrule.gif"><img src="http://www.crossref.org/images/spacer.gif" width="100" height="4"></td></tr></table>');
}