// JavaScript Document

function validateForm()
{

//check of naam leeg is
if (document.inc_contactformulier.elements['naam'].value == "")
{
alert("Vul uw naam in svp.");
document.inc_contactformulier.elements['naam'].focus();
return(false);
}

//check of email leeg is
if (document.inc_contactformulier.elements['email'].value == "")
{
alert("Vul uw e-mailadres in svp.");
document.inc_contactformulier.elements['email'].focus();
return(false);
}

//check of Email juist is
if (!checkEmail(document.inc_contactformulier.elements['email'].value))
{
alert("Vul een geldig e-mailadres in svp");
document.inc_contactformulier.elements['email'].focus();
return(false);
} 

}

// deze functie controleert de juistheid van het e-mailadres op meerdere punten
function checkEmail(emailAddress) {

var foundAtSymbol = 0;
var foundDot = 0;
var md;

// Go through each character in the email address.
for (var x=0; x<emailAddress.length - 1; x++) {
md = emailAddress.substr(x, 1);

// Is the character an @ symbol?
if (md == '@') foundAtSymbol++;

// Count how many dots there are after the @ symbol.
if (md == '.' && foundAtSymbol == 1) foundDot++;
};

// Is there only one @ symbol, and are there more than one dots?
if (foundDot > 0 && foundAtSymbol == 1) {
return true;
} else {
return false;
};

};