// sbpbsbval.js
//
//	Written by Adam Altman
//	Copyright 2001 Adam Altman
//	
//	Unauthorized use is prohibited
//	
//	Developed for: www.statbiomedical.com
//

// whitespace characters
var whitespace = " \t\n\r";
// Check whether string s is empty.
function isEmpty(s)
{   return ((s == null) || (s.length == 0))
}

// Returns true if string s is empty or 
// whitespace characters only.
function isWhitespace (s)

{   var i;

    // Is s empty?
    if (isEmpty(s)) return true;

    // Search through string's characters one by one
    // until we find a non-whitespace character.
    // When we do, return false; if we don't, return true.

    for (i = 0; i < s.length; i++)
    {   
        // Check that current character isn't whitespace.
        var c = s.charAt(i);

        if (whitespace.indexOf(c) == -1) return false;
    }

    // All characters are whitespace.
    return true;
}

function isEmail (s)
{   if (isEmpty(s)) return false;
    if (isWhitespace(s)) return false;
    
    // there must be >= 1 character before @, so we
    // start looking at character position 1 
    // (i.e. second character)
    var i = 1;
    var sLength = s.length;

    // look for @
    while ((i < sLength) && (s.charAt(i) != "@"))
    { i++
    }

    if ((i >= sLength) || (s.charAt(i) != "@")) return false;
    else i += 2;

    // look for .
    while ((i < sLength) && (s.charAt(i) != "."))
    { i++
    }

    // there must be at least one character after the .
    if ((i >= sLength - 1) || (s.charAt(i) != ".")) return false;
    else return true;
}


function validate(f){
	if (f.name.value==""){
		f.name.focus();
		alert("You must enter a Name");
		return false;
	}
	if ((f.email.value=="")||(!isEmail(f.email.value))){
		f.email.focus();
		alert("You must enter a valid Email Address");
		return false;
	}
	if (f.message.value==""){
		f.message.focus();
		alert("You must enter a Message");
		return false;
	}
	f.submit();
}