Where to action when create submit form?

I wanna to create a form like this , code is here:

<div class="callback-form">
	<h3>Request a<br> free callback!</h3>
	<form class="frm-callback" name="callback" method="post" action="" onsubmit="return validateform();">
		<div><input id="name" type="text" value="YOUR NAME" onfocus="javascript:if(this.value=='YOUR NAME')this.value='';" onblur="javascript:if(this.value=='')this.value='YOUR NAME';" onclick="javascript:if(this.value=='YOUR NAME')this.value='';" onkeypress="javascript:if(this.value=='YOUR NAME')this.value='';"></div>
		<div><input id="phone" type="text" value="YOU PHONE NUMBER" onfocus="javascript:if(this.value=='YOU PHONE NUMBER')this.value='';" onblur="javascript:if(this.value=='')this.value='YOU PHONE NUMBER';" onclick="javascript:if(this.value=='YOU PHONE NUMBER')this.value='';" onkeypress="javascript:if(this.value=='YOU PHONE NUMBER')this.value='';"></div>
		<div><input type="submit" value="call me back"></div>

As you see, in above code I put form’s action attribute is empty. Now, I want to form action to a function named get_info() in file functions.php in theme folder. How can I do that?

P/S: demo website is here http://fridgevan.kudoswebdesign.com/

In this case let 's call get_info in the end of function validateform()

Hmmm! validationform() is javascript validation function and get_info is a php function, I can not call it in the end of function validateform. Luckily, I found the way help me do what I want. Thanks for your answer :slight_smile: