problem with accessing webservice from remote pc

Hi,
I am a newbie in designing web services. In my web service, I have created a webmethod which is extracting some data from my SQL server and then show it following some queries. Now everything is running fine from my local pc.

But when I try to access my web service from a remote pc with my pc’s fixed IP (http://163.180.145.139/test1/Service.asmx) they show all the webmethods list but after clicking on any of the operations it shows:  The test form is only available for requests from the local machine. You can check it too by following the above link.

1. Plz tell me how can I solve this problem so that everyone can access my webservice and sql server data through it stored in my localhost from any remote pc over the internet.

2. Plz tell me why I can't access any data through the webservice by typing a line in the address bar like this: http://163.180.145.139/test1/Service.asmx/ShowSuppliers?str=1990. In some tutorials its said that it will work. But I am getting error: Request format is unrecognized for URL unexpectedly ending in '/ShowSuppliers'

For your information I'm using windows Xp, IIS 5, sql server 2005 enterprise edition, MVS 2005: C#  for my work. Please let me know for any further info.

Thanks in advance
Faysal