How to set focus on dropdown by its name -javascript/jquery

Since you tagged your question with jQuery, try something like

$('select[name^="dropname"]').eq(1).focus();

// $('select[name^="dropname"]') < elements whos name starts with "dropname"
// .eq(1) < select one based on its index
// .focus(); < use jQuery's focus method to set the focus

Try using jquery focus like

$("#id2").focus();

You can use

var i = 0 //or 1,2,3

document.getElementsByName('dropname['+i+']')[0].focus();

hope this will help you