"Intention is the general word implying a having something in mind as a plan or design, or referring to the plan had in mind. Intent, a somewhat formal term now largely in legal usage, connotes more deliberation (assault with an intent to kill)"
That explanation is certainly better than mine, and I find it true.
Edit: You asked for sentences; sorry.
My intention was to buy a long dress to wear as a guest at the wedding. However, after shopping awhile, I didn't find any styles of long dresses that I liked, so I bought a short one instead.
Our apartment building has a strict policy of no pets. My neighbor, George, rarely visits me. So when he knocked at my door this morning, I just knew his intent was to find my cat!
Thus, an intention is a general plan that one has in mind. An intent is really a deliberate plan.
also use this link