function getCookie( name ) { 
	var start = document.cookie.indexOf( name + "=" );     
	var len = start + name.length + 1;     
	if ( ( !start ) && ( name != document.cookie.substring( 0, name.length ) ) ) 
	{         return null;     }     
	if ( start == -1 ) return null;     
	var end = document.cookie.indexOf( ';', len );     
	if ( end == -1 ) end = document.cookie.length;     
	return unescape( document.cookie.substring( len, end ) ); 
}  
function setCookie( name, value, expires, path, domain, secure ) 
{     
	var today = new Date();     
	today.setTime( today.getTime() );    
 	if ( expires ) {        
 		expires = expires * 1000 * 60 * 60; //小时
      }   

   	var expires_date = new Date( today.getTime() + (expires) );    
    document.cookie = name+'='+escape( value ) + ( ( expires ) ? ';expires='+expires_date.toGMTString() : '' ) +        
		( ( path ) ? ';path=' + path : '' ) + ( ( domain ) ? ';domain=' + domain : '' ) + ( ( secure ) ? ';secure' : '' ); 

}  
	
function deleteCookie( name, path, domain ) {     
	if ( getCookie( name ) ) 
	document.cookie = name + '=' + ( ( path ) ? ';path=' + path : '') + ( ( domain ) ? ';domain=' + domain : '' ) + ';expires=Thu, 01-Jan-1970 00:00:01 GMT'; 
} 
 
/* set cookie */
function setCookieSimple(name, value, expires)
{
    setCookie( name,value,expires, null, null,null) ;
}