regularExpresion to exclude some characters

[Suresh]

Daniel,
If you don't mind using a javascript function with a
custom validator you can try the following.

function ContainSpecialCharacter(source, arguments)
{
var objRE = new RegExp("[:%&]");
if(objRE.exec(arguments.Value) == null)
arguments.IsValid = true;
else
arguments.IsValid = false;
}

This function contains reg exp that checks for the
existance of your special characters. If it finds it then
it returns a false failing validation else true passing
validation.

HTH,
Suresh.