See this link:
and "allows prediction of alternatively spliced isoforms" in it.
The whole paragraph:
"NCBI gnomon Gene prediction (coding region of transcript) generated via a hidden Markov model using transcript alignment constraints and protein hit information, if available; allows prediction of alternatively spliced isoforms (Souvorov, et al., 2006, NCBI); submitted by J. Ostell. "
In the upper right corner replace :"Jump to gene" to your preferred gene-name and press GO:
You will get this page:
Again on the left you can play with "gene region": intron, exons, etc.