// JavaScript Document

function isblank(s)
{
    for(var i = 0; i < s.length; i++) {
        var c = s.charAt(i);
        if ((c != ' ') && (c != '\n') && (c != '\t')) return false;
    }
    return true;
}

function is_email(str)
{
  // are regular expressions supported?
  var supported = 0;
  if (window.RegExp)
  {
    var tempStr = "a";
    var tempReg = new RegExp(tempStr);
    if (tempReg.test(tempStr)) supported = 1;
  }
  if (!supported) 
    return (str.indexOf(".") > 2) && (str.indexOf("@") > 0);
  var r1 = new RegExp("(@.*@)|(\\.\\.)|(@\\.)|(^\\.)");
  var r2 = new RegExp("^.+\\@(\\[?)[a-zA-Z0-9\\-\\.]+\\.([a-zA-Z]{2,4}|[0-9]{1,3})(\\]?)$");
  return (!r1.test(str) && r2.test(str));
}

function validate_contact_form(form)
{
	var return_value = false;
	
	var type_selected = false;
	
	if(isblank(form.name.value))
	{
		alert("Please enter your name");
		form.name.focus();
	}
	else if(isblank(form.telephone.value) && !is_email(form.email.value))
	{
		alert("Please enter a valid email address or telephone number");
		form.email.focus();
	}
	else if(isblank(form.comments.value))
	{
		alert("Please fill in the comments field");
		form.comments.focus();
	}
	else
	{
		return_value = true;
	}
	
	return return_value;
}