function isEmpty(val)
{
	if(val=="")
		return true;
	else 
		return false;
}

function validateText(field_id)
{
	var element = document.getElementById(field_id);

	if(isEmpty(element.value))
	{
		displayError(field_id, "Required");
		return false;
	}
	else
	{
		clearInfoField(field_id);
		return true;
	}
}

function validatecheckbox(field_id)
{
	var element = document.getElementById(field_id);
	if(element.checked==false)
	{
		displayError(field_id, "Required");
		return false;
	}
	else
	{
		clearInfoField(field_id);
		return true;
	}
}

function validateEmail(field_id)
{
	var element = document.getElementById(field_id);
	
	if(isEmpty(element.value))
	{
		displayError(field_id, "Required");
		return false;
	}
	else if(!isValidEmail(element.value))
	{
		displayError(field_id, "Invalid Email");
		return false;
	}
	else
	{
		clearInfoField(field_id);
		return true;
	}
}

function displayError(field_id, msg)
{
		field_id += '_info' ;
		var element = document.getElementById(field_id);
		element.className = 'input_error' ;
		element.innerHTML = msg;
}

function clearInfoField(field_id)
{
		field_id += '_info' ;
		var element = document.getElementById(field_id);
		element.className = '' ;
		element.innerHTML = '';
}

function isValidEmail(val)
{
	var emailExp = /^[\w\-\.\+]+\@[a-zA-Z0-9\.\-]+\.[a-zA-z0-9]{2,4}$/;

	if(val.match(emailExp))
		return true;
	else
		return false;
}


function isValidFileFormat(file_name)
{
	var file_extension = file_name.substring(file_name.lastIndexOf('.'), file_name.length);
	
	if( (file_extension == ".jpg") || (file_extension == ".JPG") || (file_extension == ".jpeg") || (file_extension == ".JPEG") || (file_extension == ".GIF") || (file_extension == ".gif") || (file_extension == ".PNG") || (file_extension == ".png"))
		return true;
	else
		return false;
}

function validateEquality(field_id_1, field_id_2)
{
	var element1 = document.getElementById(field_id_1);
	var element2 = document.getElementById(field_id_2);
	
	if(isEmpty(element1.value))
	{
		displayError(field_id_1, "Required");
		return false;
	}
	else if(element1.value != element2.value)
	{
		displayError(field_id_1, "Passwords do not match");
		return false;
	}
	else
	{
		clearInfoField(field_id_1);
		return true;
	}
	
}