function trim(sString) 
{
	while (sString.substring(0,1) == ' ')
	{
		sString = sString.substring(1, sString.length);
	}
	while (sString.substring(sString.length-1, sString.length) == ' ')
	{
		sString = sString.substring(0,sString.length-1);
	}
	return sString;
}

function check_mail(email)
{	
	var re3 = /^\s*([a-zA-Z0-9\._\-]{1,100})@([a-zA-Z0-9\.\-_]){1,100}\.([a-zA-Z]{2,4})\s*$/gi;
     
    if (email.length>=0 && !email.match(re3)) 
	{
		return false;
	}
	
	return true;
}

function upload_form_validation()
{
	var error = "";
	
	if(document.getElementById('upfile_0').value=="") error = error + "Please select the file you want to upload\n";
	if(document.getElementById('fileTags').value=="") error = error + "Please add some descriptive tags for your file (ex: php project, Paris photos, book chapters) \n";	

	if(document.getElementById('recipients').value!="")
	{
		var recipients = document.getElementById('recipients').value.split(",");
		
		for(i=0; i<recipients.length; i++)
		{
			//recipients[i] = trim(recipients[i]);
			if(check_mail(recipients[i]) == false)
			{
				if(recipients.length == 1)
					error = error + "The recipient's email is not valid. Please check the format (ex: email@email.com)\n";
				else
					error = error + "One of the recipient's emails is not valid. Please check the format (ex: email@email.com,email1@email1.com)\n";
				break;
			}
		}
	}
	
	if(document.getElementById('senderEmail').value!="")
	{
		if(check_mail(document.getElementById('senderEmail').value) == false)
			error = error + "Your email is not valid. Please check the format (ex: email@email.com)\n";
	}	
	
	if(document.getElementById('terms').checked==false)
		error = error + "You need to accept the terms of service (check the coresponding checkbox)\n";

	if(document.getElementById('news').checked==true && document.getElementById('senderEmail').value=="")
		error = error + "In order to receive news from us please enter your email address\n";
		
	error = "MyFreeFileHosting.com can no longer allow any uploading or downloading.\n";

	if(error != "")
	{
		alert(error);
		return false;
	}

	document.getElementById('myform').style.display="none";
	
	return uploadFiles();
}