function checkWholeForm(form) {
    var why = "";
    why += checkEmail(form.email.value);
    why += checkPassword(form.P2.value);
    why += checkUsername(form.username.value);
    why += matchPasswords(form.P1.value, form.P2.value);
    
    if (why != "") {
       alert(why);
       return false;
    }
return true;
}


function matchPasswords (P1, P2){
var error="";
if (P1 != P2){
	 error = "Passwords do not match!\n";
	}

return error; 	
}


function checkEmail (strng) {
var error="";
if (strng == "") {
   error = "You didn't enter an email address.\n";
}

    var emailFilter=/^.+@.+\..{2,3}$/;
    if (!(emailFilter.test(strng))) { 
       error = "Please enter a valid email address.\n";
    }
    else {
//test email for illegal characters
       var illegalChars= /[\(\)\<\>\,\;\:\\\"\[\]]/
         if (strng.match(illegalChars)) {
          error = "The email address contains illegal characters.\n";
       }
    }
return error;    
}



// password - between 6-8 chars, uppercase, lowercase, and numeral

function checkPassword (strng) {
var error = "";
if (strng == "") {
   error = "You didn't enter a password.\n";
}

    var illegalChars = /[\W_]/; // allow only letters and numbers
    
    if ((strng.length < 4) || (strng.length > 20)) {
        error = "Your password must be at least 4 characters long.\n";
    }
    else if (illegalChars.test(strng)) {
      error = "The password contains illegal characters.\n";
    } 
return error;    
}    


// username - 4-10 chars, uc, lc, and underscore only.

function checkUsername (strng) {
var error = "";
if (strng == "") {
   error = "You didn't enter a username.\n";
}


    var illegalChars = /\W/; // allow letters, numbers, and underscores
    if ((strng.length < 4) || (strng.length > 30)) {
       error = "Your username must be at least 4 characters long.\n";
    }
    else if (illegalChars.test(strng)) {
    error = "The username contains illegal characters.\n";
    } 
return error;
}       

function check() {
  var ext = document.f.image.value;
  ext = ext.substring(ext.length-3,ext.length);
  ext = ext.toLowerCase();
  if(ext != 'jpg') {
    alert('You selected a .'+ext+
          ' file; please select a .jpg file instead!');
    return false; }
    else
    return true; 
}