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function trim(TheString)
{
    var len;
 
    len = TheString.length;
    while(TheString.substring(0,1) == " "){ //trim left
        TheString = TheString.substring(1, len);
          len = TheString.length;
    }
 
    while(TheString.substring(len-1, len) == " "){ //trim right
        TheString = TheString.substring(0, len-1);
          len = TheString.length;
    }
    return TheString;
}
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[HTML] pobierz, plaintext 
if(trim(pole) == "" || pole == null){...}
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tresc = //tresc z twojego pola
 
regExp = /^(.*{1,})$/;
 
if( regExp.test(tresc) ){
 //jest jakis znak
}
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