function kids(){

 window.open("lesson_img/kids/pre.html","window1","toolbar=no,location=no,directories=no,status=no,menubar=no,scrollbars=no,resizable=yes,width=360,height=350");
}

function basic_begi(){

 window.open("lesson_img/basic_begi/pre.html","window1","toolbar=no,location=no,directories=no,status=no,menubar=no,scrollbars=no,resizable=yes,width=360,height=350");
}

function intermediate(){

 window.open("lesson_img/intermediate/pre.html","window1","toolbar=no,location=no,directories=no,status=no,menubar=no,scrollbars=no,resizable=yes,width=360,height=350");
}

function intro(){

 window.open("lesson_img/intro/pre.html","window1","toolbar=no,location=no,directories=no,status=no,menubar=no,scrollbars=no,resizable=yes,width=360,height=350");
}

function sympo_2007_02_25(){

 window.open("lesson_img/sympo_2007_02_25/pre.html","window1","toolbar=no,location=no,directories=no,status=no,menubar=no,scrollbars=no,resizable=yes,width=360,height=350");
}

function sympo_2008_06_29(){

 window.open("lesson_img/sympo_2008_06_29/pre.html","window1","toolbar=no,location=no,directories=no,status=no,menubar=no,scrollbars=no,resizable=yes,width=360,height=350");
}