fiesta 1.3 will not turn over please help

hi can anyone please help
i have a ford fiesta 1.3 1995.
it has been ok untill it just stopped when driving it and i had to get it towed home. it has oil and water in it the startermotor is ok and the battery is charged.
when i try to start it or turn it over, it just clicks once or twice,
i have tryed to jump start it and also tow it to try and start it and i have no luck with it can anyone help me with this problem.
please let me no
many thanks from andy2007

Can you turn the motor by hand, using a wrench on the crank pulley bolt? You are going to have to determine if the motor locked up.

my car does that i odnt know if yours has the same problem but have a check, front centre of under the bonnet there are a bunch of little wires near the very bottom check these are not wet as this will cause your car not to start up, it will just click but wont turn over, if they are wet/damp dry them with a cloth and spay them with WD-40 or a substance like that then try starting up again. like i said this may not be the problem in your car but when it doesnt start again have a quick check.