problem with accessing asp.net web service from remote pc

Hi,
I am a newbie in designing asp.net 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. I think I will get the same problem if I try to access the webservice after consuming it from a asp.net client application. 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 remote pc.

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