how to show/hide divs by select.(jquery)

Answer 1

Something like this?

var optionValue = $("#select").val();

$('#form1, #form2, #form3').hide();

switch(optionValue)
{
case 1:
  $("#form1").show();
  break;
case 2:
  $("#form2").show();
  break;
case: 3:
  $("#form3").show();
  break;
}