CSV is most oten used to input data into JMeter test scripts. The CSV Data Set Config is used to read lines from a file and to split them into variables. Follow below steps to read from csv:
Step 1: Right Click on Plan. Click on Add->Config Element->CSV Data Set Config
Step 2: Enter FileName. Use complete path if you are not in bin directory.
Step 3: Enter Variable Name. This is equal to column name in CSV.
Step 4: Enter Delimeter. Comma is Default you can use any other.
Step 5: Create New Login HTTP Request
Step 6: Enter Path of Login page
Step 7: Set Method to Post
Step 8: Set Parameter and give variable names. $ means these are variable not values.
Step 9: Select "URL Encode?" checkbox
Step 10: Run your script
You can view password read successfully using request tab of view Result Tree Listener.