function HideContent(d)  {
        document.getElementById(d).style.display = "none";
}      

function ShowContent(d, link, sale_no, lot_no)  {
        document.getElementById(d).style.display = "block";
}

function checkRequiredFields(input)
{
        var requiredFields = new Array( "to", 
                                        "from" );

        var fieldNames = new Array( "Recipient email", 
                                    "Senders email");


        var fieldCheck   = true;
        var fieldsNeeded = "\nMake sure following fields are filled out:\n\n\t";

	for(var fieldNum=0; fieldNum < requiredFields.length; fieldNum++)
	{
                if ((input.elements[requiredFields[fieldNum]].value == "") || (input.elements[requiredFields[fieldNum]].value == " ")) 
                {
			fieldsNeeded += fieldNames[fieldNum] + "\n\t";
                        fieldCheck = false;
                }
        }

        if (fieldCheck == true)
        {
                return true;
        }
        else
        {
                alert(fieldsNeeded);
                return false;
        }
}