Problem with uploaded images in wordpress

Thanks for you concern. These links are very useful.
I am sorry for not explaining my question properly.
Let me explain it.

Here is the code i am using in my custom page template (single-page.php)

<div class=”post-content”>
<p>
<img class=”” src=”” width=”” height=”” alt=””>
</p>
</div>
Now i want that when a user post any image from the post, these attributes of the image tag should be filled dynamically.
How to do that?
Meanwhile, i am reading those links you have provided me.

EDIT:
i have gone through the function
wp_get_attachment_image_src();
i just want to know how to find the id of the uploaded image dynamically so that i can use the above function to work.