I would like to start by saying that i am completely new to Ajax so please bear with me. I have to calculate the sum of all the prices sold between the two dates taken as an input.
Here is my table
     Product_ID----ProductName------price------OrderDate
    ---  1  --------  Chair -------- 7 ------ 2015-01-05
    ---  2  --------  Lamp --------- 14 ----- 2015-01-16
    ---  3  --------  Table -------- 9 ------ 2015-02-25
Here's my HTML
<html>
<head>
<script>
function showPrice(str) {
    if (str == "") {
        document.getElementById("txtHint").innerHTML = "";
        return;
    } else { 
        if (window.XMLHttpRequest) {
            // code for IE7+, Firefox, Chrome, Opera, Safari
            xmlhttp = new XMLHttpRequest();
        } else {
            // code for IE6, IE5
            xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");
        }
        xmlhttp.onreadystatechange = function() {
            if (xmlhttp.readyState == 4 && xmlhttp.status == 200) {
                document.getElementById("txtHint").innerHTML = xmlhttp.responseText;
            }
        }
        xmlhttp.open("GET","getprice.php?q="+str,true);
        xmlhttp.send();
    }
}
</script>
</head>
<body>
<form>
 <input type="date" name="startdate">
 <p>To</p>
 <input type="date" name="enddate">
 <br><br>
 <button type="submit" name="submit"       
onclick="showAge(this.value)">Calculate</button>
</form>
<br>
<div id="txtHint"><b>Age  will be listed here...</b></div>
</body>
</html>
And here is my MySQL query
SELECT SUM(price) AS TotalPrice 
FROM orders
WHERE OrderDate >= '11/11/2014' AND OrderDate <= '15/11/2015'
So my question is, how can i send two dates as input using ajax to calculate the sum of prices?