new sharepoint web application can not access using hostname

HI

i created a web application on port 90 or 443 with a host header name,

but i can not access this site using host name.

- when i create application suppose i give portalinternet host name and url become 

http://portalinternet:90 but i removed portno from url

- iis bindings are exists for this hostname in  web application on port

- i added this host name in host file in  WFE server with IP of wfe

10.171.3.xx portalinternet

in browser when i access the site : http://portalinternet 

i can not access and view

adil