<!DOCTYPE HTML> <html> <head> <title>Untitled</title> <meta charset="utf-8"> </head> <body> <select id="CategoryTree" name="category_sid[tree][1]"> <option value="0">Все категории</option> <option selected="selected" title="/Car/" value="4"> Автомобили(3)</option> <option title="/Motorcycle/" value="8"> Мотоциклы(2)</option> <option title="/Trucks/" value="13"> Грузовики(1)</option> </select> <div id="avto" style="display:block">инфо об Автомобилях</div> <div id="moto" style="display:none">инфо о Мото</div> <div id="trucks" style="display:none">инфо о Грузовиках</div> <script> document.getElementById("CategoryTree") .onchange = function () { var b = { 4: "avto", 8: "moto", 13: "trucks" }, c = this.value, a; for (a in b) document.getElementById(b[a]) .style.display = 0 == c || c == a ? "block" : "none" }; </script> </body> </html>