如何在php中使用javascript函数？

Question

There are two tables in a page. One is for Friday and other is for Saturday. I want to set the choice limit of radio button selection from a table. User can not select more than 3 slots out of 4 slots from Friday table. How can I call a javascript function for a table? How can I do this? Here is my php code and javascript function.

This javascript function is working for both table. When I select 3 radio button from any table it shows "You can not add more than 3". But I want this only for Friday table not for Saturday.

1. PHP code:

                 for($time=0; $time<4; $time++){
                   $q.= "<td colspan='1' valign='top' width='25%'>";
                       $q.= "<table id='ash'>";
                       $q.= "<tr id='grey'>";
                       if($day==1){
                           if($time==0){
                               $q.= "<th width='50%'></th></tr>";
                           }else if($time==1){
                               $q.= "<th width='50%'></th></tr>";
                           }else if($time==2){
                               $q.= "<th>Reg.</th>";
                               $q.= "<th width='50%'>2:30 pm - 5:00 pm</th>";
                               $q.= "<th>Sec</th><th>Remaining</th></tr>";
                           }else{
                               $q.= "<th>Reg.</th>";
                               $q.= "<th width='50%'>5:00 pm - 7:30 pm</th>";
                               $q.= "<th>Sec</th><th>Remaining</th></tr>";
                           }
                       } 
                     else{
                           $q.= "<th>Reg.</th>";
                           if($time==0){
                               $q.= "<th width='50%'>8:30 am - 11:00 am</th>";
                           }else if($time==1){
                               $q.= "<th width='50%'>11:00 am - 1:30 pm</th>";
                           }else if($time==2){
                               $q.= "<th width='50%'>2:30 pm - 5:00 pm</th>";
                           }else{
                               $q.= "<th width='50%'>5:00 pm - 7:30 pm</th>";
                           }
                           $q.= "<th>Sec</th><th>Remaining</th></tr>";
                       }
                       $query1 = "SELECT tab1.*, tab2.course_name, tab2.course_type FROM routine AS tab1, course_info AS tab2"; 
                       $result = mysql_query($query1);
                       if ($result && mysql_num_rows($result) > 0) {
                           while($row = mysql_fetch_assoc($result)){
                               $course = $row["course_code"];
                               $sec = $row["section"];
                               $type = $row["course_type"];
                               if(course_completed($std_id, $course)){
                                   if(already_selected($course, $sec, $std_id, $year, $sem)){
                                       $q.= "<tr bgcolor='#00FF33'><td><input type='radio' id='course_".$day."_".$time."' name='".$day.$time."' value='".$course.",".$sec.",".$type."' checked='checked' onclick='changeRadioValue(\"".$day."_".$time."\")' /></td>";
                                   }
                                   else{
                                       $q.= "<tr bgcolor='#00FF33'><td><input type='radio' id='course_".$day."_".$time."' name='".$day.$time."' value='".$course.",".$sec.",".$type."' onclick='changeRadioValue(\"".$day."_".$time."\")' /></td>";
                                   }
                               }
   
                          else{
   
                                   if(already_selected($course, $sec, $std_id, $year, $sem)){
                                       $q.= "<tr><td><input type='radio' id='course_".$day."_".$time."' name='".$day.$time."' value='".$course.",".$sec.",".$type."' checked='checked' onclick='changeRadioValue(\"".$day."_".$time."\")' /></td>";
                                   }else{
                                       $q.= "<tr><td><input type='radio' id='course_".$day."_".$time."' name='".$day.$time."' value='".$course.",".$sec.",".$type."' onclick='changeRadioValue(\"".$day."_".$time."\")' /></td>";
                                   }
                               }
   

2. JavaScript function

   $("input[type='radio']").change(function(){
       var count = $("input[type='radio']:checked").length;
       if(count>3){
           $(this).prop('checked', false);
         alert("You cannot add more than 3");
       }
   });
   

Answer 1

Try this:

<?php
if(condition) {
    ?>
    <script>//JS Code</script>
    <?php
}
?>

When you page loads, if the condition is true the js code between the script tags will run, you can also link another js file instead of writing code.