You need to dynamicly handle it by yourself, with the help of javascript...
Attach a 'onchange' event function to the input text you want the function control entry user in real-time.
Inside this function, define the code to verify / correct the actual 'value" attribut content.
Many kind of implementations are possible ;)
[ EDIT ]
'onkeypress" event is preferable: check next post for code example and further explanations...
HTML:
<input type="text" onkeypress="inputHandler(this, filter, correct);">
[ EDIT ]
'oninput' event is more useful in this case ( check next posts )
JS:
function inputHandler(src, filterCallback, fixCallback) {
if ( ! filterCallback(src.value) ) src.value=correct(src.value);
}
function filter(val) {
/* code for return true if 'val' is valid, else return false */
}
function correct(val) {
/* code for return corrected value of 'val': simply need to retrieve invalid char */
}
Not tested ( means verified this one ), but it's the idea for a generic parametric handler ( you can define and apply how many filter you want ).
I change 'onchange' event by replacing it with 'onkeypress" because from memory, it's less problematic ( onchange is only called when entry is validate by the user, meaning when element lost focus, on keypress occurs each time user press a key, so each time the value is supposed to have changed )
'oninput' is clearly the better choice, because it's design especially for <input> element ( new event in html5 ).
It's first difference/adavantage with keypress/keydown/keyup ( verified just now ) is that it will be fired in case of change due to a paste, or a drop, while key-family event don't ;)
I wrote simple example, check it in my codes. "Code for Garrrach_hazem". Try to input letters and numbers
I can comment it later because i need to go now.
