I hate this task: „Delete default value of an input text on click„. Many times i use code like this
<input type="text" value="email@email.com" name="email"
onblur="if (this.value == '') {this.value = 'email@email.com';}"
onfocus="if (this.value == 'email@email.com') {this.value = '';}" />
Forget about this! I would recommend you try HTML5 solution below which uses the placeholder attribut.
<input name="Email" type="text" value="" placeholder="email@email.com" />