Using JS to control the Select label's default selection based on the data received __JS

This is in the last unit of the BDQN project, do an OA project, interim requirements Control Select selection:

<TD align= "Left" >
	<input type= "hidden" value= "${u.usersex}" id= "Sex" >
	<select name= " U.usersex "width=" 30% "id=" gender ">
		<option value=" Women "id=" woman "> Women </option>
		<option Value = "Male" id= "man" > </option>
	</select>
</td>

Here is the code in JS:

<script type= "Text/javascript" >
			
			var sex = document.getElementById ("Sex"). Value;
			if (sex = = "Man") {
				document.getElementById ("Gender"). Options[1].selected=true;
			} else{
				document.getElementById ("Gender"). Options[0].selected=true;
			}
			Check userName
			function CheckName () {
				var name = document.getElementById ("UserName"). Value;
				if (name = = NULL | | | name = = "") {
					alert ("User name cannot be empty!");
					return;
				}
			
			Check Usertel
			function Checktel () {
				var tel = document.getElementById ("Usertel"). Value;
				if (tel = = NULL | | tel = = "") {
					alert ("Cell phone number cannot be empty!");
					return;
				}
				if (Tel.length!=) {
					alert ("Please enter the correct 11-digit mobile number.") ");
					return;
				}
			
			Returns the previous page
			function Backit () {
				history.back ();
			}
			
			Commit
			function SaveIt ()
			{
				document.forms[0].submit ();
			}
			
</script>