根据变量值将数据发送到不同的表

I have a table called "wifi" and another table called "bluetooth" on my mysql database I have a $string from a form if the string contains "wifi" I want to set the $tbl_name= to "wifi" , else set it to "bluetooth" then send the data to the appropriate table I havent found any example, am I doing the right thing ? Yes, I'm new :)I have a table called "wifi" and another table