var form = "";
var submitted = false;
var error = false;
var error_message = "";

function check_input(field_name, field_size, message) {
  if (form.elements[field_name] && (form.elements[field_name].type != "hidden")) {
    var field_value = form.elements[field_name].value;

    if (field_value.length < field_size) {
      error_message = error_message + "* " + message + "\n";
      error = true;
    }
  }
}

function check_email(field_name, message) {
	if (form.elements[field_name] && (form.elements[field_name].type != "hidden")) {
		var field_value = form.elements[field_name].value;
		
		if((field_value.search(/\S/)!=-1) && ((/^[a-zA-Z0-9._-]+@([a-zA-Z0-9.-]+\.)+[a-zA-Z.]{2,5}$/).exec(field_value)==null)){
			error_message = error_message + "* " + message + "\n";
			error = true;
		}
	}
}

function check_radio(field_name, message) {
  var isChecked = false;

  if (form.elements[field_name] && (form.elements[field_name].type != "hidden")) {
    var radio = form.elements[field_name];

    for (var i=0; i<radio.length; i++) {
      if (radio[i].checked == true) {
        isChecked = true;
        break;
      }
    }

    if (isChecked == false) {
      error_message = error_message + "* " + message + "\n";
      error = true;
    }
  }
}

function check_checkbox(field_name, message) {
	var isChecked = false;
	
	if (form.elements[field_name] && (form.elements[field_name].type != "hidden")) {
		var checkbox = form.elements[field_name];
		
		if(checkbox.length)
		{ //multiple checkboxes
			for(i=0;i<checkbox.length;i++)
			{
				if (checkbox[i].checked == true) {
					isChecked = true;
				}	
			}
		}
		else
		{ //single checkbox
			if (checkbox.checked == true) {
				isChecked = true;
			}	
		}
		
		if (isChecked == false) {
			error_message = error_message + "* " + message + "\n";
			error = true;
		}
	}
}

function check_select(field_name, field_default, message) {
  if (form.elements[field_name] && (form.elements[field_name].type != "hidden")) {
    var field_value = form.elements[field_name].value;

    if (field_value == field_default) {
      error_message = error_message + "* " + message + "\n";
      error = true;
    }
  }
}
function check_numeric(field_name, message) {
  if (form.elements[field_name] && (form.elements[field_name].type != "hidden")) {
    var field_value = form.elements[field_name].value;

    if (field_value.length>1 && isNaN(field_value)) {
      error_message = error_message + "* " + message + "\n";
      error = true;
    }
  }
}
 
  
function check_register(form_name,verification_code) {
  if (submitted == true) {
    alert("This form is already submitted, please wait until the page refreshes.");
    return false;
  }

  error = false;
  form = form_name;
  error_message = "Error : Please correct the following\n";
  check_input('user_name',2,'Please enter your name.');
  check_input('user_address',4,'Please enter your address.');
  check_input('user_phone',10,'Please enter 10 digit phone no.');
  check_input('email_address',4,'Please enter your email address.');
  check_email('email_address', 'Please enter valid email.');
  check_input('user_comments',1,'Please enter your comment.');
 check_input('ver_image',1,'Please enter the verification code listed above.');
	if((form.ver_image.value != '') && (form.ver_image.value != verification_code))
	{
		error_message += "* Please enter the verification code correctly.";
		error = true;
	}


  if (error == true) {
    alert(error_message);
    return false;
  } else {
    submitted = true;
    return true;
  }
}