$(document).ready(function(){
  $(".required").after('<span class="ast_req">*<span>');
  $(".ast_req").css('color','red').css('font-weight','bold');
})
 

function validate(btn){
  isValid = true; 
  $(".required").each(function(){
   if(!$(this).val() || $(this).val() == "Please Select" || $(this).val() == "Select Tech"){
    $(this).css('border-color','red');
    isValid = false;
    
   }
   else{$(this).css('border-color','#000');}
  })
  
  if(!isValid && $("#err_msg").length == 0)
    $(btn).after('&nbsp;<span style="color:red;" id="err_msg">Required fields (marked with *) must be filled.</span>');
  
  return isValid;
}