Getting a Symbolic Variable from the user using input

How to get a Symbolic variable as an input from the user? for example when the input prompt comes up if the user inputs nothing or a '?' sign, a symbolic variable automatically gets created. I tried using the code below and then entering something like "syms u" to create the variable but it gives this error: Invalid expression. Check for missing multiplication operator, missing or unbalanced delimiters, or other syntax error. To construct matrices, use brackets instead of parentheses.

Fx=input('Horizental Force on Node');

Answer 1

[madhan ravi]

"How to get a Symbolic variable as an input from the user?"

prompt = 'Horizontal force on node: ';
str = input(prompt,'s');

[madhan ravi]

The above will do the work you need.

[Morteza Ghafoori]

With this, an empty symbolic variable will be created if the user inputs nothing and that totally suits me. Thanks

[madhan ravi]

you are welcome