Double value attribute in front-page.php

I just found that the sign-up form throw double value attribute into email input form, but do not know what exactly to remove, so need some help.

Code:

        <form action="<?php get_template_directory(); ?>" id="contactForm1" class="signupform" method="post">
 
 //the line bellow is complicated
 
            <input onfocus="if (this.value == 'e-mail address') {this.value = '';}" onblur="if (this.value == '') {this.value = 'e-mail address';}" name="email" value="e-mail address" type="text" value="<?php if (isset($_POST['email'])) echo $_POST['email']; ?>" id="email" />
 
 
            <input type="submit" value="Sign Up" name="submit"/>
            <input type="hidden" name="submitted" id="submitted" value="true" />
            <?php if ($emailError != '') { ?>
                                    <br />
            <span class="error"><?php echo $emailError; ?></span>
            <?php } ?>
        </form>

 

Please clarify your issue little more, so that we can give you the exact solution.