Can't Post facebook URL using facebook SDK - facebook

Question

I have a webapplication that I use to reshare existing post as follow
1)get the post details using https://graph.facebook.com/UserID_postID?access_token=AAA (works fine)
2)fill the a data of the new post from the old one and try to resend it but there is some strange behviour
if I use
oldpost.link = newpost.link it doesnt nothing appear on the wall but if I used
oldpost.link="\""newpost.link+"\"" works and the post appear on facebook wall but the link appears corputted as invalid.invalid/
function getPost(userID, postID, token) {
jQuery.getJSON("https://graph.facebook.com/" + userID + "_" + postID + "?access_token=" + token, function (post) {
here is the code any idea please
var newPost = {};
newPost.message = "hi";
if (post.link != "" && post.link != null && post.link != "undefined") {
newPost.link = "\"" + post.link + "\"";
}
if (post.name != "" && post.name != null && post.name != "undefined") {
newPost.name = "\"" + post.name + "\"";
}
if (post.picture != "" && post.picture != null && post.picture != "undefined") {
newPost.picture = "\"" + post.picture + "\"";
}
if (post.description != "" && post.description != null && post.description != "undefined") {
newPost.description = "\"" + post.description + "\"";
}
doPost(newPost);
});
}
function doPost(newPost) {
FB.api('/me/feed', 'post',
newPost, function (response) {
if (!response || response.error) {
alert(' Denied Access');
} else {
alert('Success');
}
});
}