How to solve the judgment in the phpform-php Tutorial

Judgment in the phpform {foreachfrom $ selectAryitemselect }{{ if $ select. idsid }}& nbsp ;{{$ select. name }}{ {if }{{ foreach} php form judgment
{Foreach from = $ selectAry item = select }}
{If $ select. id = sid }}
{$ Select. name }}
{/If }}
{{/ Foreach }}
I output it cyclically here, but I want him to output one that corresponds to the id in my form. how can I make a judgment? I cannot make a judgment like this.
If the judgment is gone, two outputs will be output.

PHP code

JScript code

  Function sendData () {var uid = document. getElementById ('den _ uid '). value; var sid = document. getElementById ('den _ Sid '). value; var text = document. getElementById ('part _ text '). value; var rideo = document. getElementsByName ('Part [is_good] '); var is_good; if (text = ''| text = 'Enter your opinion. the number of words is within 50 words ') {alert ('please give your opinion, otherwise the vote will be invalid! '); Return false;} alert (sid); for (var I = 0; I
  

------ Solution --------------------
Do you want to give the form a unique identifier?
Js, jquery, and others are not mentioned at all.