ajax url not able to append the correct data

I'm having issue with the dynamic url in the AJAX call. here is the function could you please suggest why its not working

function SF_UpdateParentContract() {
    var param = {
        UnitPrice: parseFloat($("#txtSaleAmt").val()) + parseFloat($("#txtTaxAmt").val())    
    }   
    var uPath = 'https:\\www.syz.com\token' + $("#OppLineId").val(); 
     alert($("#OppLineId").val()); $.ajax({
            type:"PATCH",
            beforeSend: function (request)
            {
                request.setRequestHeader("Authorization", "OAuth " +Token);
            },
            url: uPath,
            data:JSON.stringify(param),
            contentType:"application/json",
            processData: false,
            success: function(response) {                
            },
            error : function (data, errorThrown,status) {
                alert("Update failed");              
            },
            complete: function(xhr, statusText){    

            }
    });
}

Here I'm always getting uPath as https:\www.syz.com\token, I m not able to get the value of $("#OppLineId").val(); but in alert statement i'm able to see entire url which is https:\www.syz.com\token\A2323

any idea why ajax url is not considering this request and only making a call to the https:\www.syz.com\token url.

Thanks