jquery span tag set va;ue code example
Example 1: set span text
$("#spanID").text('your text');
Example 2: jquery change the label of a value in select
$("#FIELDID").find("option:contains(\"OptionLabel\")").text('NewLabel');
$("#spanID").text('your text');
$("#FIELDID").find("option:contains(\"OptionLabel\")").text('NewLabel');