I'm trying to customize a validation script that came with my theme. It works fine, but I want to make it so the comment field is not required. I have tried commented out everything related but then I was getting errors.

here is the javascript
Code:
// var $mjq for better adaptation and work with other libraries
var $mjq = jQuery.noConflict();
$mjq(function(){
	$mjq(document).ready(function(){
		 $mjq(".help-inline").each(function() {
			$mjq(this).css('display', 'none');
		 });
	});
	$mjq("#inputEmail").bind('blur', is_valid_email);
	$mjq("#inputName").bind('blur', is_valid_name);
	// $mjq("#textarea").bind('blur', is_valid_comment);
    $mjq('#validForm').bind('submit', function(e) {
        if (!is_valid_form())
            return false;

        e.preventDefault();
        $mjq("#result").html('');
        var data = $mjq(this).serialize();

        $mjq.ajax({
            url: "newsletter_form.php",
            type: "post",
            dataType : "json",
            data: data,
            success: function(data) {
                var alertClass;
                if(data.error === true){
                    alertClass = 'alert-error';
                }else{
                    alertClass = 'alert-success';
                    $mjq('#validForm').closest('form').find("input[type=text], textarea").val("");
                }
                $mjq("#result").html(returnHtml(alertClass, data.message));
            },
            error: function(data) {
                $mjq("#result").html(returnHtml('alert-error', data));
            }
        });
    });
});

function returnHtml(alertClass, html){
    return '<div class="alert  '+alertClass+'"><button type="button" class="close" data-dismiss="alert">&times;</button>'+html+'</div>';
}

// Email validate
function is_valid_email() {
	$this = $mjq("#inputEmail");
	var pattern = new RegExp(/^((([a-z]|\d|[!#\$%&'\*\+\-\/=\?\^_`{\|}~]|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])+(\.([a-z]|\d|[!#\$%&'\*\+\-\/=\?\^_`{\|}~]|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])+)*)|((\x22)((((\x20|\x09)*(\x0d\x0a))?(\x20|\x09)+)?(([\x01-\x08\x0b\x0c\x0e-\x1f\x7f]|\x21|[\x23-\x5b]|[\x5d-\x7e]|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])|(\\([\x01-\x09\x0b\x0c\x0d-\x7f]|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF]))))*(((\x20|\x09)*(\x0d\x0a))?(\x20|\x09)+)?(\x22)))@((([a-z]|\d|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])|(([a-z]|\d|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])([a-z]|\d|-|\.|_|~|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])*([a-z]|\d|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])))\.)+(([a-z]|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])|(([a-z]|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])([a-z]|\d|-|\.|_|~|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])*([a-z]|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])))\.?$/i);
	if(pattern.test($this.val())){ // valid
		if ($this.closest(".control-group").hasClass("error")) 
			$this.closest(".control-group").removeClass("error");
		$this.siblings(".help-inline").css("display", "none");
		return true;
	} else { // error
		if (!$this.closest(".control-group").hasClass("error")) 
			$this.closest(".control-group").addClass("error");
		$this.siblings(".help-inline").css("display", "block");
		return false;
	}
}
// Name validate
function is_valid_name() {
	$this = $mjq("#inputName");
	if($this.val().length>0){ // valid
		if ($this.closest(".control-group").hasClass("error")) 
			$this.closest(".control-group").removeClass("error");
		$this.siblings(".help-inline").css("display", "none");
		return true
	} else { // error
		if (!$this.closest(".control-group").hasClass("error")) 
			$this.closest(".control-group").addClass("error");
		$this.siblings(".help-inline").css("display", "block");
		return false;
	}
}
// Comment validate
// function is_valid_comment() {
// 	$this = $mjq("#textarea");
// 	if($this.val().length>0){ // valid
// 		if ($this.closest(".control-group").hasClass("error")) 
// 			$this.closest(".control-group").removeClass("error");
// 		$this.siblings(".help-inline").css("display", "none");
// 		return true
// 	} else { // error
// 		if (!$this.closest(".control-group").hasClass("error")) 
// 			$this.closest(".control-group").addClass("error");
// 		$this.siblings(".help-inline").css("display", "block");
// 		return false;
// 	}
// }
// Form validate
function is_valid_form() {
	var ret = true;
	if (!is_valid_name()) var ret = false;
	if (!is_valid_email()) var ret = false;
	// if (!is_valid_comment()) var ret = false;
	return ret;
}
here is the html form
HTML Code:
<div id="result">

                </div>

                <form name="contactForm" id="validForm" method="POST" action="newsletter_form.php">
                    <div class="control-group">
                        <label class="control-label" for="inputName">NAME<sup>*</sup></label>
                        <div class="controls">
                            <input name="name" type="text" class="span4" id="inputName" placeholder="Name">
                            <span class="help-inline">Please fill your name</span>
                        </div>
                    </div>

                    <div class="control-group">
                        <label class="control-label" for="inputEmail">EMAIL<sup>*</sup></label>
                        <div class="controls">
                            <input name="email" type="text" class="span4" id="inputEmail" placeholder="Email">
                            <span class="help-inline">Please correct your email</span>
                        </div>
                    </div>

                    <div class="control-group">
                        <label for="textarea" class="control-label">COMMENT<sup>*</sup></label>
                        <div class="controls">
                            <textarea name="comment" rows="4" class="span7" id="textarea"></textarea>
                            <span class="help-inline">Please write a comment</span>
                        </div>
                    </div>

                    <?php
                            require_once('config.php');
                            require_once('recaptchalib.php');
                            if($use_recaptcha === true){
                                echo recaptcha_get_html($publickey);
                            }
                        ?>
                    <div class="control-group form-button-offset">
                        <input type="submit" id="submit" class="btn" value="Send Message" />
                    </div>
                </form>

Any ideas on how to make it so the comment field is not required?