ajax - Include the drop-down value into a SQL query in ColdFusion -

i have page shows list of students. want use dropdown implement filter. when option 1 (high school students) selected shows high school students, when option 2 selected (college students) selected shows college students , on. query be:

select firstname, lastname, age  students  studentcategory = #dropdownvalue# 

is there way without using javascript nor submit button. trying pass dropdown value url not sure how change url when option selected dropdown. appreciate help.

to answer question, add onchange first select.

<select  name="doesntmatter" onchange="document.location.href='?studentcategory='+this.value;"> 

however consider using ajax faster.