Hi there,
I have a search function on my web site and am trying to figure why this code does not work. The search function needs to accept numbers 0 to 9, letters a to z, cap letters A to Z, spaces, no spaces, and dashes. Right now the function accepts all but am having problems with search term that contains numbers and letters.

For example, one of the search term in the database is: W12-543-TR-G5-2001

So when a user searches for that particular data, entering "W12-543-TR-G5-2001" or "W12543TRG52001" should render the results. My current codes is not accepting these terms.

string searchterm= "";
for (int i = 0; i < _keyword.Length; i++)
{
if ((_keyword[i] >= 'a' && _keyword[i] <= 'z') || (_keyword[i] >= 'A' && _keyword[i] <= 'Z') || (_keyword[i] >= '0' && _keyword[i] <= '9') || _keyword[i] == ' ' || _keyword[i] == '-')
{
searchterm+= _keyword[i];
}
}
_keyword = searchterm;

Any help or suggestions is greatly appreciated!

Searching should be done in the database. You need to determine if there is a set structure for your data, in other words, how it is stored in the db. Then you have to construct your search parameters to search your DB correctly.