function showEmailForm() {
 var ef = document.getElementById("emailform");
 ef.style.display = "block";   
}

function hideEmailForm() {
 var ef = document.getElementById("emailform");
 ef.style.display = "none";   
}

function validEmailForm() {
    document.getElementById("ctl00_ContentPlaceHolder1_EmailNameFrom").value = trim(document.getElementById("ctl00_ContentPlaceHolder1_EmailNameFrom").value)
    document.getElementById("ctl00_ContentPlaceHolder1_EmailAddressFrom").value = trim(document.getElementById("ctl00_ContentPlaceHolder1_EmailAddressFrom").value)
    document.getElementById("ctl00_ContentPlaceHolder1_EmailNameTo").value = trim(document.getElementById("ctl00_ContentPlaceHolder1_EmailNameTo").value)
    document.getElementById("ctl00_ContentPlaceHolder1_EmailAddressTo").value = trim(document.getElementById("ctl00_ContentPlaceHolder1_EmailAddressTo").value)
    document.getElementById("ctl00_ContentPlaceHolder1_EmailBody").value = trim(document.getElementById("ctl00_ContentPlaceHolder1_EmailBody").value)

    if ((document.getElementById("ctl00_ContentPlaceHolder1_EmailNameFrom").value == '' ) ||
        (document.getElementById("ctl00_ContentPlaceHolder1_EmailAddressFrom").value == '' ) ||
        (document.getElementById("ctl00_ContentPlaceHolder1_EmailNameTo").value == '' ) ||
        (document.getElementById("ctl00_ContentPlaceHolder1_EmailAddressTo").value == '' ) ||
        (document.getElementById("ctl00_ContentPlaceHolder1_EmailBody").value == '' ) )
    {
        alert('Please fill all field');
        return false;
    }

    return true;
}

function trim(s)
{
    if (s == null)
    {
        return s;
    }

    var i;
    var beginIndex = 0;
    var endIndex = s.length - 1;

    for (i=0; i<s.length; i++)
    {
        if (s.charAt(i) == ' ' || s.charAt(i) == '　')
        {
            beginIndex++;
        }
        else
        {
            break;
        }
    }

    for (i = s.length - 1; i >= 0; i--)
    {
        if (s.charAt(i) == ' ' || s.charAt(i) == '　')
        {
            endIndex--;
        }
        else
        {
            break;
        }
    }

    if (endIndex < beginIndex)
    {
        return "";
    }

    return s.substring(beginIndex, endIndex + 1);
}