function checkText(strng, defStrng){
	var error="";
	if (strng == "" || strng == defStrng) {
		error = "- " + defStrng + ".\n";
		return error;
	}
	return error;
}

function checkTextEmpty(strng, defStrng){
	var error="";
	if (strng == "") {
		error = "- " + defStrng + ".\n";
		return error;
	}
	return error;
}

function checkZip(strng) {
	var defVal = "Enter ZIP";
	var error="";
	var valid = "0123456789-";
	var hyphencount = 0;
	
	if(strng == defVal) strng = "";
	
	if (strng.length!=5 && strng.length!=10) {
		error = "- Please enter a 5 digit or 5 digit+4 zip code.\n";
		return error;
	}
	for (var i=0; i < strng.length; i++) {
		temp = "" + strng.substring(i, i+1);
		if (temp == "-") hyphencount++;
		if (valid.indexOf(temp) == "-1") {
			error += "- Invalid characters in your zip code.\n";
			return error;
		}
		if ((hyphencount > 1) || ((strng.length==10) && ""+strng.charAt(5)!="-")) {
			error += "- The zip code hyphen character should be used with a properly formatted 5 digit+four zip code, like '12345-6789'.\n";
			return error;
	   }
	}
	return error;
}

function checkEmail (strng) {
	var error="";
	if (strng == "") {
	   error = "- 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;    
}


// phone number - strip out delimiters and check for 10 digits

function checkPhone (strng) {
	var error = "";
	var valid = "0123456789";
	if (strng == "") {
	   error = "- You didn't enter a phone number.\n";
	}
	var stripped = strng.replace(/[\(\)\.\-\ \+]/g, ''); //strip out acceptable non-numeric characters

    if (isNaN(parseInt(stripped)) || !isInteger(stripped)) {
       error = "- The phone number contains illegal characters.";
  
    }
    if (!(stripped.length >= 10)) {
		error = "- The phone number is the wrong length. Make sure you included an area code.\n";
    } 
	return error;
}

function isInteger(s)
{   var i;
    for (i = 0; i < s.length; i++)
    {   
        // Check that current character is number.
        var c = s.charAt(i);
        if (((c < "0") || (c > "9"))) return false;
    }
    // All characters are numbers.
    return true;
}

// 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 < 6) || (strng.length > 8)) {
       error = "- The password is the wrong length.\n";
    }
    else if (illegalChars.test(strng)) {
      error = "- The password contains illegal characters.\n";
    } 
    else if (!((strng.search(/(a-z)+/)) && (strng.search(/(A-Z)+/)) && (strng.search(/(0-9)+/)))) {
       error = "- The password must contain at least one uppercase letter, one lowercase letter, and one numeral.\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 > 10)) {
       error = "- The username is the wrong length.\n";
    }
    else if (illegalChars.test(strng)) {
    error = "- The username contains illegal characters.\n";
    } 
	return error;
}       


// non-empty textbox
function isEmpty(strng) {
	var error = "";
  if (strng.length == 0) {
     error = "- The mandatory text area has not been filled in.\n"
  }
	return error;	  
}

// was textbox altered
function isDifferent(strng) {
	var error = ""; 
  if (strng != "Can\'t touch this!") {
     error = "- You altered the inviolate text area.\n";
  }
	return error;
}

// exactly one radio button is chosen
function checkRadio(checkvalue) {
	var error = "";
   if (!(checkvalue)) {
       error = "- Please check a radio button.\n";
    }
	return error;
}

// valid selector from dropdown list
function checkDropdown(choice,msg) {
	var error = "";
    if ((choice == 0) || (choice == "Please Select ...")) {
    error = "- " + msg + "\n";
    }    
	return error;
}