You can use JavaScript (e.g. with jQuery) to allow only specific characters:

// Catch all events related to changes $('#textbox').on('change keyup', function() { // Remove invalid characters var sanitized = $(this).val().replace(/[^0-9]/g, ''); // Update value $(this).val(sanitized); }); 

Here is a fiddle.

Same thing with support for floats:

// Catch all events related to changes $('#textbox').on('change keyup', function() { // Remove invalid characters var sanitized = $(this).val().replace(/[^0-9.]/g, ''); // Remove the first point if there is more than one sanitized = sanitized.replace(/\.(?=.*\.)/, ''); // Update value $(this).val(sanitized); }); 

And here is another fiddle.

You can use JavaScript (e.g. with jQuery) to allow only specific characters:

// Catch all events related to changes $('#textbox').on('change keyup', function() { // Remove invalid characters var sanitized = $(this).val().replace(/[^0-9]/g, ''); // Update value $(this).val(sanitized); }); 

Here is a fiddle.

Same thing with support for floats:

// Catch all events related to changes $('#textbox').on('change keyup', function() { // Remove invalid characters var sanitized = $(this).val().replace(/[^0-9.]/g, ''); // Remove the first point if there is more than one sanitized = sanitized.replace(/\.(?=.*\.)/, ''); // Update value $(this).val(sanitized); }); 

And here is another fiddle.

Update: Although you might not need this, here is a solution that allows a leading minus sign.

// Catch all events related to changes $('#textbox').on('change keyup', function() { // Remove invalid characters var sanitized = $(this).val().replace(/[^-0-9]/g, ''); // Remove non-leading minus signs sanitized = sanitized.replace(/(.)-+/g, '$1'); // Update value $(this).val(sanitized); }); 

3rd fiddle

And now a final solution that allows only valid decimals (including floats and negative numbers):

// Catch all events related to changes $('#textbox').on('change keyup', function() { // Remove invalid characters var sanitized = $(this).val().replace(/[^-.0-9]/g, ''); // Remove non-leading minus signs sanitized = sanitized.replace(/(.)-+/g, '$1'); // Remove the first point if there is more than one sanitized = sanitized.replace(/\.(?=.*\.)/g, ''); // Update value $(this).val(sanitized); }); 

Final fiddle

You can use JavaScript (e.g. with jQuery) to allow only specific characters:

// Catch all events related to changes $('#textbox').on('change keyup', function() { // Remove invalid characters var sanitized = $(this).val().replace(/[^0-9]/g, ''); // Update value $(this).val(sanitized); }); 

Here is a fiddle.

You can use JavaScript (e.g. with jQuery) to allow only specific characters:

// Catch all events related to changes $('#textbox').on('change keyup', function() { // Remove invalid characters var sanitized = $(this).val().replace(/[^0-9]/g, ''); // Update value $(this).val(sanitized); }); 

Here is a fiddle.

Same thing with support for floats:

// Catch all events related to changes $('#textbox').on('change keyup', function() { // Remove invalid characters var sanitized = $(this).val().replace(/[^0-9.]/g, ''); // Remove the first point if there is more than one sanitized = sanitized.replace(/\.(?=.*\.)/, ''); // Update value $(this).val(sanitized); }); 

And here is another fiddle.