function validateFormOnSubmit(theForm) {
var reason = "";

  reason += validateEmail(theForm.YourEmail);
  reason += validateEmpty(theForm.name);
  reason += validateEmpty2(theForm.Date);
  reason += validateEmpty3(theForm.Date2);
      
  if (reason != "") {
    alert("Some fields need correction:\n" + reason);
    return false;
  }


}
function validateEmpty(fld) {
    var error = "";
 
    if (fld.value.length == 0) {
        fld.style.background = 'Red'; 
        error = "You have not filled in your name.\n"
    } else {
        fld.style.background = 'White';
    }
    return error;  
}

function validateEmpty2(fld) {
    var error = "";
 
    if (fld.value.length == 0) {
        fld.style.background = 'Red'; 
        error = "Please select your Check In Date.\n"
    } else {
        fld.style.background = 'White';
    }
    return error;  
}

function validateEmpty3(fld) {
    var error = "";
 
    if (fld.value.length == 0) {
        fld.style.background = 'Red'; 
        error = "Please select your Check Out Date.\n"
    } else {
        fld.style.background = 'White';
    }
    return error;  
}


function trim(s)
{
  return s.replace(/^\s+|\s+$/, '');
}
function validateEmail(fld) {
    var error="";
    var tfld = trim(fld.value);                        // value of field with whitespace trimmed off
    var emailFilter = /^[^@]+@[^@.]+\.[^@]*\w\w$/ ;
    var illegalChars= /[\(\)\<\>\,\;\:\\\"\[\]]/ ;
   
    if (fld.value == "") {
        fld.style.background = 'Red';
        error = "You didn't enter an email address.\n";
    } else if (!emailFilter.test(tfld)) {              //test email for illegal characters
        fld.style.background = 'Red';
        error = "Please enter a valid email address.\n";
    } else if (fld.value.match(illegalChars)) {
        fld.style.background = 'Red';
        error = "The email address contains illegal characters.\n";
    } else {
        fld.style.background = 'White';
    }
    return error;
}