function validateFormOnSubmit(signup) {
	var reason = "";
	
	reason += validatefname(signup.f_name);
	reason += validatelname(signup.l_name);
	reason += validateUsername(signup.username);
	reason += validatePassword(signup.password);
	reason += validateEmail(signup.e_add);
	reason += validatesquesname(signup.s_ques);
	reason += validatesansname(signup.s_ans);
		      
	if (reason != "") {
	  alert("Some fields are not valid:\n\n" + reason);
	  return false;
	}
	
	return true;
}

function validatefname(fld) {
    var error = "";
  
    if (fld.value.length == 0) {
        fld.style.background = '#FFF167'; 
        error = "Your First Name has not been filled in.\n"
    } 
    else {
        fld.style.background = 'White';
    }
    return error;   
}

function validatelname(fld) {
    var error = "";
  
    if (fld.value.length == 0) {
        fld.style.background = '#FFF167'; 
        error = "Your Last name has not been filled in.\n"
    } 
    else {
        fld.style.background = 'White';
    }
    return error;   
}

function validatesquesname(fld) {
    var error = "";
  
    if (fld.value.length == 0) {
        fld.style.background = '#FFF167'; 
        error = "You did not enter a Security Question.\n"
    } 
    else {
        fld.style.background = 'White';
    }
    return error;   
}

function validatesansname(fld) {
    var error = "";
  
    if (fld.value.length == 0) {
        fld.style.background = '#FFF167'; 
        error = "You did not enter a Security Answer.\n"
    } 
    else {
        fld.style.background = 'White';
    }
    return error;   
}

function validateUsername(fld) {
    var error = "";
    var illegalChars = /\W/; // allow letters, numbers, and underscores
 
    if (fld.value == "") {
        fld.style.background = '#FFF167'; 
        error = "You didn't enter a username.\n";
    } else if ((fld.value.length < 3) || (fld.value.length > 15)) {
        fld.style.background = '#FFF167'; 
        error = "The username should be between 3 and 15 characters long.\n";
    } else if (illegalChars.test(fld.value)) {
        fld.style.background = '#FFF167'; 
        error = "The username contains illegal characters.\n";
    } else {
        fld.style.background = 'White';
    } 
    return error;
}

function validatePassword(fld) {
    var error = "";
    var illegalChars = /[\W_]/; // allow only letters and numbers 
 
    if (fld.value == "") {
        fld.style.background = '#FFF167';
        error = "You didn't enter a password.\n";
    } else if ((fld.value.length < 8) || (fld.value.length > 15)) {
        error = "The password should be between 8 and 15 characters long. \n";
        fld.style.background = '#FFF167';
    } else if (illegalChars.test(fld.value)) {
        error = "The password contains illegal characters.\n";
        fld.style.background = '#FFF167';
    } else if (fld.value!=signup.password_c.value){
	    error = "The password confirmation does not match.\n";
	    fld.style.background = '#FFF167';
	    signup.password_c.style.background = '#FFF167';
    } else {
        fld.style.background = 'White';
        signup.password_c.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 = '#FFF167';
        error = "You didn't enter an email address.\n";
    } else if (!emailFilter.test(tfld)) {              //test email for illegal characters
        fld.style.background = '#FFF167';
        error = "Please enter a valid email address.\n";
    } else if (fld.value.match(illegalChars)) {
        fld.style.background = '#FFF167';
        error = "The email address contains illegal characters.\n";
    } else {
        fld.style.background = 'White';
    }
    return error;
}