var BLANK = '';
var USERNAME_DEFAULT  = 'enter your username:';
var PASSWORD_DEFAULT  = 'enter your password:';
var USERNAME_ID  = 'usernameform';
var PASSWORD_ID  = 'passwordform';

function clear_box(element)
{
		if(element.value == USERNAME_DEFAULT) element.value = BLANK;
		else if (element.value == PASSWORD_DEFAULT) element.value = BLANK;
}

function reset_box(element)
{
		if(element.value == BLANK)
		{
			if(element == document.getElementById(USERNAME_ID)) element.value = USERNAME_DEFAULT;
			else if(element == document.getElementById(PASSWORD_ID)) element.value = PASSWORD_DEFAULT;
		}
}

function reset_all()
{
		document.getElementById(USERNAME_ID).value = USERNAME_DEFAULT;
		document.getElementById(PASSWORD_ID).value = PASSWORD_DEFAULT;
}