validation, multiple radio button in each row

I am displaying three radio buttons in each row for each employee, how to validate for empty check.

<td><input type="radio" name="stf_att_<?php echo $stf_id ;?>" value="p" /></td>
<td><input type="radio" name="stf_att_<?php echo $stf_id ;?>" value="a" /></td>
<td><input type="radio" name="st开发者_Python百科f_att_<?php echo $stf_id ;?>" value="l" /></td>

am using another table to display values using id for each employee. have to use name="" for validation but in name am using id from database, how i do with js or php

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if(document.getElementById('staff').checked) {
  //will come here is a particular radio is checked

}

You can mark one of the radio buttons as checked (checked="checked") in the HTML code, which would guarantee that one radio button is always selected. Since one of the option is true for all the employees, think this would solve your problem.

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Add a class name to each of the three radio buttons like their names. (stf_att_<?php echo $stf_id ;?>). And use the function below to validate radio buttons:

function checkRadio(classname) {
    var el = document.getElementsByClassName(classname);
    for(var i=0; i<el.length; i++) {
        if(el[i].checked) {
            return 1;
        }
    }
    return 0;
}

It is so much easier using a javascript library like jquery.